A follow up on gh-4305, fix failing args.test.py

To make it possible to develop and test related features on
systems without systemd.

WITH_SYSTEMD cmake flag is used to generate systemd related files:
unit, generator script, etc. To keep this behavior and make it possible
to use NOTIFY_SOCKET without other systemd-related stuff,
I added WITH_NOTIFY_SOCKET cmake flag.

It also required some changes to support other OS:

SOCK_CLOEXEC (not available on macOS) flag for socket()
is replaced with `fcntl(fd, F_SETFD, FD_CLOEXEC)` which has the same effect.

MSG_NOSIGNAL flag for sendmsg is also not available on macOS.
However it has SO_NOSIGPIPE flag for setsockopt which disables SIGPIPE.
So it requires different solution for different OS. Inspired by
https://nwat.xyz/blog/2014/01/16/porting-msg_more-and-msg_nosigpipe-to-osx/

Have to reduce send-buffer size to 4MB because larger values
are not supported on macOS by default. This value should be enough
for all systems because notification messages are usually less than 1KB.

Fixes #4436

System-wide dynamic libraries usually (always?) have NEEDED and RUNPATH
tags in a dynamic section (as `readelf -d /usr/lib/lib<...>.so` shows),
so when we link, say, with libssl.so, which depends on libz.so, a linker
does not complain against unresolved symbols that can be found in Z
library (if it is installed within a system).

Things are different when we linking with a static library. Say, when we
linking with libssl.a, which contains an unresolved symbol from Z
library, a linker reports an error. It is not possible to store an
information where to find unresolved symbols (NEEDED / RUNPATH) in a
static library (AFAIK).

We depend on three libraries that are depend on Z library: libcurl,
libssl and libcrypto (two latter are part of OpenSSL). When one of those
libraries is linked statically we should link with libz.so or libz.a
(depending on BUILD_STATIC flag). The patch doing exactly this.

The patch changes OPENSSL_LIBRARIES variable to fix the issue with
static linking of OpenSSL libraries. It also changes CURL_LIBRARIES in
the same way, however this does not alter any visible behaviour, because
OPENSSL_LIBRARIES is added to CURL_LIBRARIES. The latter change was made
to unify the way to choose libraries to link with: it is pure
refactoring part.

Fixes #4437.

Tuple fields can be named, accessed by name, indexed by name, but
till this commit field names couldn't be used in update
operations. Now it is possible.

This patch is a teaser of updates by JSON path.

Part of #1261

Rope will not be used by tuple_update directly in
next patches.

Rope library stores alloc, split and free functions by pointer,
that is a huge slog at performance, as any other virtual
function call. There is no reason, why the rope library may not
become a template, except historical ones.

The patch not only removes virtual functions, but also makes rope
deletion almost no-op in case if free() function is not defined.

A second motivation point of that patch is that original rope
structure was too big. Again, because it stored several pointers
to functions. In forthcoming patches on #1261 multiple ropes can
be created per each update, so it makes sense to reduce size of
this structure.

They are always region_aligned_alloc and region pointer. Lets use
them always inside tuple_update.c, with no necessity to pass
explicitly.

The patch is motivated by forthcoming updates by JSON path, which
will strongly complicate and perhaps slow down the tuple_update.c
code. The present patch as well as some next ones should smooth
these problems.

A manual action is needed after pulling of this commit to actually use
the downstream repository instead of the upstream one:

sed -i -e 's@https://github.com/curl/curl.git@https://github.com/tarantool/curl.git@' .git/config

It is part of our processes to use forked repositories for submodules.

Suggested by Konstantin Osipov.

Cleaned up the .gitlab-ci.yml file from duplicating
code - added templates that storres the needed
configuration values for different jobs.
Also moved the static_build from 'deploy' tag to
'deploy_test' tag to be sure that tests will not
be run under high load.

This problem is similar to the one fixed in commit
3c6c1cc9 (lua:fix decimal comparison
with nil)
We should handle box.NULL the same way.

Closes #4454

* Added "fragile" option with a list of tests that are not intended to
  be run in parallel with others. The format of the list is the same as
  for "disabled" option (#187, PR #188).
* Ensured that non-parallel test suites and fragile tests will be run
  only when all parallel ones will be finished (PR #188).
* Fixed reporting in case of lack of temporary result (PR #172).

CentOS 6 and FreeBSD 12 implementations of getpwuid() rewind
setpwent()-{getpwent()}-endpwent() loop to a start that leads to a hang
during pwd.getpwall() invoke. The same is true for a getgrgid() call
during setgrent()-{getgrent()}-endgrent() loop.

The commit modifies pwd module to avoid getpwuid() calls during passwd
database traversal and to avoid getgrgid() calls when traversing groups.

The commit also fixes the important regression on CentOS 6 after
f5d8331e ('lua: workaround
pwd.getpwall() issue on Fedora 29'): tarantool hungs during startup due
to added getpwall() call. This made tarantool unusable on CentOS 6 at
all.

Aside of that the commit fixes another pwd.getgrall() problem: the
function gaves password entries instead of group entries.

Fixes #4428.
Fixes #4447.
Part of #4271.

app-tap.tarantoolctl.test.lua fails after
17df9edf ('tarantoolctl: allow to start
instances with delayed box.cfg{}').

The commit fixes the test case that did check that an error is reported
if box.cfg() was not called in an instance script.

Follows up #4435.
Fixes #4448.

This change is related to #4391. The objective was to collect additional
information about modules, but it's hard to do without changing API.

This patch will allow to monkey-patch report generation and achieve the
same results without interfering the daemon behavior.

There is a problem with calculating .msg_namelen field
of msghdr struct. Instead of

    .msg_name   = &sa,
    .msg_namelen = sizeof(sa.sun_family) + strlen(sd_unix_path),

it must set as

    .msg_namelen = sizeof(sa) // larger value than current invalid one

It works on linux but when I tried to enable this feature for macOS
it didn't (maybe because of different order of fields in the struct).

Instead of fixing calculation, I've replaced original sendmsg call
with sendto, because it's a convenient shortcut which
simplifies code and can prevent such mistakes.

Required for #4436

`tarantoolctl start` patches box.cfg two times:
1) before the init script to set default values and enforce some others,
2) after the init script to prevent changing a pid_file in runtime.

The second patching fails if an init file does not call
box.cfg{} before it's finished. This can take a place in apps with
managed instances which receive configuration from external server.

This patch moves the second patching into the box.cfg
wrapper created during the first patching. So the second patching
is performed only after box.cfg{} was invoked, so it does not fail anymore.

However there is relatively minor flaw for applications that
invoke box.cfg{} after init script is finished:
`tarantoolctl start` goes to background only when box.cfg{} is called.
Though this is not the case for daemon management systems like systemd,
as they handle backgrounding on their side

Fixes #4435

@TarantoolBot document
Title: tarantoolctl allows to start instances without a box.cfg{}

tarantoolctl now works for instances without box.cfg{} or
with delayed box.cfg{} call. This can be managed instances which receive
configuration from external server.

For such instances `tarantoolctl start` goes to background when
box.cfg{} is called, so it will wait until options for box.cfg are received.
However this is not the case for daemon management systems like systemd,
as they handle backgrounding on their side.

This function implements common way of precise comparison between
unsigned integer and floating point values (doubles). Currently, it is
used in tuple comparators, but we need the same thing in SQL. Hence,
let's move it to header containing set of utilities.

To compare floating point values and integers in SQL functions
compare_uint_float() and compare_int_float() are used. Unfortunately,
they contain bug connected with checking border case: that's not correct
to cast UINT64_MAX (2^64 - 1) to double. Proper way is to use exp2(2^64)
or predefined floating point constant. To not bother fixing function
which in turn may contain other tricky places, let's use instead already
verified double_compare_uint64(). So that we have unified way of
integer<->float comparison.

`apt-get update <...>` fails on Debian Buster on docker_bootstrap goal
(see #4331 for the similar issue).

Added a description how to change dependencies in .travis.mk.

Closes #4422

@TarantoolBot document
Title: Introduce <WITH ENGINE> clause for CREATE TABLE statement

To allow user to specify engine as per table option, CREATE TABLE
statement has been extended with optional <WITH ENGINE = engine_name>
clause. This clause comes at the end of CREATE TABLE statement.
For instance:

CREATE TABLE t_vinyl (id INT PRIMARY KEY) WITH ENGINE = 'vinyl';

Name of engine is considered to be string literal ergo should be
enclosed in single quotation marks and be lower-cased. Note that engine
specified in WITH ENGINE clause overwrites default engine, which is set
via 'pragma sql_default_engine'.

Error logging in engine_find() seems to be redundant: error message is
displayed twice (since its callers always push error on the top).  Let's
remove this duplication.

Name duplicates are allowed for savepoints (both in our SQL
implementation and in ANSI specification). ANSI SQL states that previous
savepoint should be deleted. What is more, our doc confirms this fact
and says that "...it is released before the new savepoint is set."
Unfortunately, it's not true - currently old savepoint remains in the
list. For instance:

SAVEPOINT t;
SAVEPOINT t;
RELEASE SAVEPOINT t;
RELEASE SAVEPOINT t; -- no error is raised

Let's fix this and remove old savepoint from the list.

This allows us to completely remove SQL specific struct Savepoint and
use instead original struct txn_savepoint.

This procedure is processed in several steps. Firstly, we add name
to struct txn_savepoint since we should be capable of operating on named
savepoints (which in turn is SQL feature). Still, anonymous (in the sense
of name absence) savepoints are also valid. Then, we add list (as
implementation of stailq) of savepoints to struct txn: it allows us to
find savepoint by its name. Finally, we patch rollback to/release
savepoint routines: for rollback tail of the list containing savepoints
is cut (but subject of rollback routine remains in the list); for
release routine we cut tail including node being released.

We are going to merge struct psql_txn with struct txn as a part of SQL
integration into NoSQL, so let's move counter of deferred foreign key
violations directly to struct txn.

Closes #4413

@TarantoolBot document
Title: update operations on decimal fields.

tuple:update and space:update now support deicmal operands for
arithmetic operations ('+' and '-'). The syntax is as usual:
```
d = box.tuple.new(decimal.new('1'))
---
...
d:update{{'+', 1, decimal.new('0.5')}}
---
- [1.5]
...
```

Insertion ('!') and assignment ('=') are also supported:
```
a = decimal.new('1')
---
...
b = decimal.new('1e10')
---
...
c = decimal.new('1e-10')
---
...
d = box.tuple.new{5, a, 6, b, 7, c, "string"}
---
...
d
---
- [5, 1, 6, 10000000000, 7, 0.0000000001, 'string']
...

d:update{{'!', 3, dec.new('1234.5678')}}
---
- [5, 1, 1234.5678, 6, 10000000000, 7, 0.0000000001, 'string']
...
d:update{{'=', -1, dec.new('0.12345678910111213')}}
---
- [5, 1, 6, 10000000000, 7, 0.0000000001, 0.12345678910111213]

When performing an arithmetic operation ('+', '-'), where either the
updated field or the operand is decimal, the result will be decimal.

When both the updated field and the operand are decimal, the result
will, of course, be decimal.

...
```

Closes #4333

@TarantoolBot document
Title: Document decimal field type.

Decimals may now be stored in spaces. A corresponding field type is
introduced: 'decimal'. Decimal values are also allowed in 'scalar',
'any' and 'number' fields.

'decimal' field type is appropriate for both memtx HASH and TREE
indices, as well as for vinyl TREE index.

```
To create an index 'pk' over a decimal field, say
```
tarantool> box.space.test:create_index('pk', {parts={1, 'decimal'}})
---
- unique: true
  parts:
  - type: decimal
    is_nullable: false
    fieldno: 1
  id: 0
  space_id: 512
  type: TREE
  name: pk
...
```
Now you can insert some decimal values:
```
tarantool> for i = 1,10 do
         > box.space.test:insert{decimal.new((i-5)/10)}
         > end
---
...
```
tarantool> box.space.test:select{}
---
- - [-0.4]
  - [-0.3]
  - [-0.2]
  - [-0.1]
  - [0]
  - [0.1]
  - [0.2]
  - [0.3]
  - [0.4]
  - [0.5]
...
```
Decimals may alse be inserted into `scalar` and `number` fields. In this
case all the number values are sorted correctly:
```
tarantool> box.schema.space.create('test')
tarantool> box.space.test:create_index('pk', {parts={1, 'number'}})
tarantool> box.space.test:insert{-1.0001, 'number'}
---
- [-1.0001, 'number']
...

tarantool> box.space.test:insert{decimal.new(-1.00001), 'decimal'}
---
- [-1.00001, 'decimal']
...

tarantool> box.space.test:insert{-1, 'number'}
---
- [-1, 'number']
...

tarantool> box.space.test:insert{decimal.new(-0.999), 'decimal'}
---
- [-0.999, 'decimal']
...

tarantool> box.space.test:insert{-0.998, 'number'}
---
- [-0.998, 'number']
...

tarantool> box.space.test:insert{-0.9, 'number'}
---
- [-0.9, 'number']
...

tarantool> box.space.test:insert{-0.95, 'number'}
---
- [-0.95, 'number']
...

tarantool> box.space.test:insert{decimal.new(-0.92), 'decimal'}
---
- [-0.92, 'decimal']
...

tarantool> box.space.test:insert{decimal.new(-0.971), 'decimal'}
---
- [-0.971, 'decimal']
...

tarantool> box.space.test:select{}
---
- - [-1.0001, 'number']
  - [-1.00001, 'decimal']
  - [-1, 'number']
  - [-0.999, 'decimal']
  - [-0.998, 'number']
  - [-0.971, 'decimal']
  - [-0.95, 'number']
  - [-0.92, 'decimal']
  - [-0.9, 'number']
...

```
Uniqueness is also preserved between decimals and other number types:
```
tarantool> box.space.test:insert{-0.92}
---
- error: Duplicate key exists in unique index 'pk' in space 'test'
...

tarantool> box.space.test:insert{decimal.new(-0.9)}
---
- error: Duplicate key exists in unique index 'pk' in space 'test'
...

```

You can also set decimal fields in space format:
```
tarantool> _ = box.schema.space.create('test')
---
...

tarantool> _ = box.space.test:create_index('pk')
---
...

tarantool> box.space.test:format{{name='id', type='unsigned'}, {name='balance', type='decimal'}}
---
...

tarantool> box.space.test:insert{1}
---
- error: Tuple field 2 required by space format is missing
...

tarantool> box.space.test:insert{1, 'string'}
---
- error: 'Tuple field 2 type does not match one required by operation: expected decimal'
...

tarantool> box.space.test:insert{1, 1.2345}
---
- error: 'Tuple field 2 type does not match one required by operation: expected decimal'
...

tarantool> box.space.test:insert{1, decimal.new('1337.420')}
---
- [1, 1337.420]
...

```

Update decNumber library, add methods to convert decimals to uint64_t
and int64_t, add unit tests.
Also replace decimal_round() function with decimal_round_with_mode() to
allow setting rounding mode.
We need to round with mode DEC_ROUND_DOWN in to_int64 conversions in
order to be consistent with double to int conversions.
It will be needed to compute hints for decimal fields.

Prerequisite #4333

This patch adds the methods necessary to encode and decode decimals to
MsgPack. MsgPack EXT type (MP_EXT) together with a new extension type
MP_DECIMAL is used as a record header.

The decimal MsgPack representation looks like this:
+--------+-------------------+------------+===============+
| MP_EXT | length (optional) | MP_DECIMAL | PackedDecimal |
+--------+-------------------+------------+===============+
The whole record may be encoded and decoded with
mp_encode_decimal() and mp_decode_decimal(). This is equivalent to
performing mp_encode_extl()/mp_decode_extl() on the first 3 fields and
decimal_pack/unpack() on the PackedDecimal field.

It is also possible to decode and encode decimals to msgpack from lua,
which means you can insert decimals into spaces, but only into unindexed
fields for now.

Follow up #692
Part of #4333

Prior to this patch format checking was broken for 'i' (integer) and 'N'
(big-endian integer). pickle.pack() rejected negative integers with
these formats. Fix this

When a number having a positive exponent is encoded, the internal
decPackedFromNumber function returns a negative scale, which differs
from the scale, returned by decimal_scale(). This leads to errors in
decoding. Account for negative scale in decimal_pack() and
decimal_unpack().

Follow-up #692

Previously decimal comparison with nil failed with following error:
`expected decimal, number or string as 2 argument`.
Fix this. Throw a more verbose error in case of '>', '<', '>=', '<='
and fix equality check.

Follow-up #692

Hold libcurl-7.65.3. This version is not affected by the following
issues:

* #4180 ('httpc: redirects are broken with libcurl-7.30 and older');
* #4389 ('libcurl memory leak');
* #4397 ('HTTPS seem to be unstable').

After this patch libcurl will be statically linked when
ENABLE_BUNDLED_LIBCURL option is set. This option is set by default.

Closes #4318

@TarantoolBot document
Title: Tarantool dependency list was changed

* Added build dependencies: autoconf, automake, libtool, zlib-devel
  (zlib1g-dev on Debian).
* Added runtime dependencies: zlib (zlib1g on Debian).
* Removed build dependencies: libcurl-devel (libcurl4-openssl-dev on
  Debian).
* Removed runtime dependencies: curl.

The reason is that now we use compiled-in libcurl: so we don't depend on
a system libcurl, but inherit its dependencies.

This is a workaround for systemd-nss issue:
https://github.com/systemd/systemd/issues/9585

The following error is observed on app-tap/pwd.test.lua on Fedora 29
(glibc-2.28-26.fc29, systemd-239-12.git8bca462.fc29) when tarantool is
linked with libcurl w/o GSS-API support:

 | builtin/pwd.lua:169: getpwall failed [errno 2]: No such file or directory

Such tarantool build lacks of libselinux.so.1 transitive dependency
(tarantool -> libcurl.so.4 -> libgssapi_krb5.so.2 -> libkrb5support.so.0
-> libselinux.so.1) and strace shows the following calls when
pwd.getpwall() is invoked first time:

 | openat(AT_FDCWD, "/lib64/libselinux.so.1", O_RDONLY|O_CLOEXEC) = 7A
 | <...>
 | access("/etc/selinux/config", F_OK)     = -1 ENOENT (No such file or directory)

It looks like a part of libselinux initialization code and is invoked
during execution of a last ffi.C.getpwent() call that returns `nil` as a
result and left errno set to ENOENT. Our pwd module set errno to zero
before getpwent() call and expects that it will be preserved if no
unrecoverable errors occur. It seems that this expectation is not meet
due to the systemd-nss issue linked above.

Second and next getpwall() calls will succeed, so the commit adds an
extra getpwall() during pwd module load. This workaround is disabled on
FreeBSD due to another issue: #4428 ('getpwall() hangs on FreeBSD 12').

See also the previous related commit:
efccac69 ('lua: fix error handling in
getpwall and getgrall').

Follows up #3766.
Part of #4318.

Added static build using Dockerfile on Centos 7 for release
commit criteria only. Added the cleanup for cmake generating
CMakeCache.txt files and CMakeFiles directories to avoid of
cmake localy created setup failing inside the docker after
the whole tarantool path was copied into it. Added testing
into the static build, running only when RUN_TESTS environment
variable set to non empty value, used in gitlab-ci job to run
the testing after the build.

Closes #3668

We remove an LSM tree from the scheduler queues as soon as it is
dropped, even though the tree may hang around for a while after
that, e.g. because it is pinned by an iterator. As a result, once
an index is dropped, it won't be dumped anymore - its memory level
will simply disappear without a trace. This is okay for now, but
to implement snapshot iterators we must make sure that an index
will stay valid as long as there's an iterator that references it.

That said, let's delay removal of an index from the scheduler queues
until it is about to be destroyed.

There's no reason to use a special method instead of the generic
space_execute_dml for applying rows received from a master during the
initial join stage. Moreover, using the special method results in not
running space.before_replace trigger, which makes it impossible to, for
example, update space engine on a replica, see the on_schema_init test
of the replication test suite.

So this patch removes the special method altogether and makes the code
that used it switch to space_execute_dml.

Closes #4417

We must enable SMALL_DELAYED_FREE_MODE to safely use a memtx snapshot
iterator. Currently, we do that in checkpoint related callbacks, but if
we want to reuse snapshot iterators for other purposes, e.g. feeding
a read view to a newly joined replica, we better hide this code behind
snapshot iterator constructors.