ucol_open() expects null-terminated string.
GCC doesn't initialize locale name buffer in RelWithDebInfo.

Fixes #2819

It is appeared that ICU v50 supports CLRD-22 when ICU v51+ supports
CLRD-23+. One of the CLRD-23 changes comparing to CLRD-22 is
local script collates before other scripts. In general that means
that having different ICU version we get different order with
non-Latin locales. The main problem is that a run that was sorted
with one version of tarantool becomes unsorted in another.

Fix tests that depends on that order and disable collation in vinyl.

Older versions of gcc do not support designated initializers.

Fixes 9a880ae6 ("Turn class Handler into struct space_vtab").

PackageCloud doesn't support Ubuntu Artful yet.

Follow up e3d97f6d

Closes #2805

The typo caused the following box.schema.user.info() failure if the user
was granted a permission to use a sequence:

  tarantool> box.schema.user.info()
  ---
  - error: 'builtin/box/schema.lua:1542: assign to undeclared variable ''seq'''
  ---

Class Handler contains only function pointers so we can easily convert
it to a C struct. This is needed to introduce internal C API to perfrom
DML requests on spaces which is required by SQL.

Needed for #2776

 - Engines should inherit struct space if they need to store engine
   specific data per space.
 - Engine::createSpace() now returns struct space instead of Handler.
 - Engines should overwrite Handler::destroy() to implement struct space
   destructor.

This is a step towards converting class Handler to struct space_vtab.

Needed for #2776

Currently, the format is stored in Handler and can be retrieved with
Handler::format(). The only reason for such a layer of indirection is
that the format should be created by an Engine method and currently it
is created by Engine::createSpace(). Let's introduce a separate method
for create a space format, Engine::createFormat(), and move the format
back to where it belongs, i.e. to struct space.

This is a step towards converting class Handler to struct space_vtab.

Needed for #2776

We gain no benefit from having them separated from corresponding
MemtxSpace::execute* methods.

This is a step towards converting class Handler to struct space_vtab.

Needed for #2776

space->handler->engine->... looks ugly. Since all Handler methods
receive space as an argument anyway, let's move engine to struct space.

This is a step towards converting class Handler to struct space_vtab.

Needed for #2776

Make new option in index part - collation - where user can pass
a name of a collation that he wants to use for comparison of the
field.

Fix #2649

Add a new space that contains collation definitions for future
index collation and more.

Add a collation cache for fast retrieving a collation object by
its name.

Needed for #2649

Introduce coll object that allows to compare strings.
Add coll_def structure and functions for its setup.
Add unit test.

Needed for #2649

Support [{field=<field_no>, type=<type>}, ...] index part format
both in box.space._index and box.schema.index.create() Lua API.

box.space_index now supports the following formats of index parts:

 1. <field_no>, <type>, <field_no>, <type>, ... -- Tarantool 1.6.0+
 2. [[<field_no>, <type>], ...] -- Tarantool 1.6.6+
 3. [{field=<field_no>, type=<type>}] -- Tarantool 1.7.6+, this patch

box.schema.upgrade() converts format #1 to #2. Format #2 is not converted
automatically to #3 yet. Let's extend box.schema.upgrade() to do that later
in order to keep upward compatibility for existing 1.7.x customers.

Lua API now supports the following formats:

1. [<field1_no>, <type1>, ,..] -- Tarantool 1.6.0+
2. [{field=<field_no>, type=<type>}] -- Tarantool 1.7.6+, this patch

In addition to format #2, [{<field_no>, type = <type>}] and
[<field_no>, <type>, may_be_added_in_the_future=xxx}] shortcut is supported.
box.schema.space.create() automatically converts format #1 to #2,
therefor all new indexes will have the new format.

Closes #2802

By some philosophic reasons it was decided to name functions
that deal with old format by name with a suffix - version of
tarantool when the format was initially introduced instead of
last version when this format was used.

Change type of 'map' argument to const char ** and return in it
the end of parsed msgpack map.

Move opt_def functions from alter.cc to opt_def.c.
Make no logical changes.

Headers duplicates are written in string separated with comma
Except special headers described in:
https://nodejs.org/api/http.html#http_message_headers

Relates to #2658

Fixes #2658

In a case of collision of field and method names, the field name have
higher priority.

Closes #1014

Aliases will allow to call tuple methods, when tuple has fields with
same names as methods. In such a case a field name has higher
priority and the tuple method with the same name becomes inaccessible
via tuple:...() API.

Needed for #1014

* Add package.search function
* Fix failing tests after patch for new loaders

Closes #2797

A patch by Alexander Turenko.

Fixes #2782

Closes #2639

It's unclear how to perform access checks in this case. Let's forbid it
explicitly until there's a user request for this feature.

- Fix the test case on macOS
- Replace os.execute("cp ...") with fio.symlink()
- Don't depend on files from other tests

Follow up #2767

- Add loader for current working directory
- Add loader for rocks searching in higher dirs like npm
- Remove rocks from `package.path` and `package.cpath`

Closes #2767

Since commit c0a30d17 ("sequence: speed up allocation of sequence
data tuple during checkpoint") sequence_data_iterator_next() does not
throw an exception, so the whole thing can be moved to sequence.c.

 - Add a new schema object class, 'sequence', which can be passed to
   box.schema.{grant,revoke} to grant access to a sequence.
 - To use a sequence (i.e. call next(), set(), or reset() on it), the
   user must either be the owner of the sequence or has a permission to
   write to it.
 - This also holds for sequences attached to spaces: the user can only
   insert a tuple to a space if he has a write access to the sequence
   attached to the space. UPDATE/DELETE do not require access to a
   sequence.
 - Automatically generated sequences are special: it can be used for
   auto increment (by passing nil to INSERT) even if the user was not
   explicitly granted access to it - it is enough to have write access
   to the space.

See #389