Reload schema after DDL SQL operations.

Closes #2608

unit/bitvec.test.c - implemented
This test is an C implementation of
sql-tap/bitvec.test.lua and sql-tap/bitvec.test.tcl

- sql-tap/bitvec.test.lua removed

Closes #2590

See https://github.com/tarantool/doc/issues/235#issuecomment-313196971

Closes #2605

coio_call() must not release stack until all work is done.
Repeat yielding until task is completed in a worker thread.

Fixes #2604

Usage:

    tarantoolctl rocks install ROCK - install a rock
    tarantoolctl rocks remove ROCK - remove a rock
    tarantoolctl rocks show ROCK - show information about an installed rock
    tarantoolctl rocks search PATTERN - search repository for rocks
    tarantoolctl rocks list - list all installed rocks

There are no other commands, options, configuration files. Our official
repository (http://rocks.tarantool.org) works out of the box. All rocks
are installed to ${PWD}/.rocks directory to support separate rocks trees
per project, as proposed by #2067. Rockspec can use "tarantool >= 1.7.x"
inside dependencies = {} block to depend on a specific Tarantool version.

LuaRocks has been slightly hacked to support custom configuration
via site_config.lua. There are no other changes in the upstream code.
It is not a fork and it isn't going to be a fork. All formats, layouts
and rockspecs are 100% compatible with the upstream LuaRocks 2017-07-10.

This feature intentionally doesn't have CMake option to disable it,
because it should be provided on all available platforms out of the box.

Other changes:

 * Add ${PWD}/.rocks to default package.path/package.cpath
 * Hack tarantoolctl to display subcommands in --help.
   Currently command line arguments handling are not perfect, but
   it can be fixed only by a new argparse implementation.

Closes #2067

A part of #1451

No semantic changes.

Needed for #1451

No semantic changes.

Needed for #1451

No semantic changes.

Needed for #1451

No semantic changes.

Needed for #1451

Follow up 6015e0df

We didn't completely removed temp database from SQL right now,
so we need to initialize ALL fatabases at time of box.cfg{}
in order to avoid such initialization on runtime.

sql-tap/func.test.lua was resetted to its previous state
because of changes with mistakes

sql-tap/select7.test.lua - modified, expected output
changed

Closes #944

Do not use BOX_NAME_MAX as size of static buffers. Further it will
be strongly increased.

Part of #944

- Updated error messages for exceeded number of trigger chain activations
and for maximum number of terms in compound SQL statements
- Rename and fix regresssion tests for #2548 and #2550

Add regression test for the #2251 issue.
Problem was resolved earlier.

Closes #2251

This flag is needed to skip records corresponding to dropped and
incomplete runs on recovery, because given VY_LOG_CREATE_RUN the
vy_recovery_iterate() callback can't tell if the run is used or
going to be dropped. This flag needlessly complicates the code of
vy_recovery_iterate(), which is supposed to simply replay all records
recovered from the log, not try to be smart. Let's get rid of it and
instead add a hint to vy_log_record indicating that a run created by
VY_LOG_CREATE_RUN is going to be dropped.

vy_prepare_truncate_space() doesn't need to make directories for
truncated indexes - they must already exist as the indexes were
created. It just needs to create initial range for each of them.
Factor out vy_index_init_range_tree() out of vy_index_create()
and use it instead where appropriate.

We have vy_recovery_lookup_index() function to look up an index in a
recovery context by id and vy_recovery_iterate_index() to iterate over
ranges, runs, and slices of a found index. vy_recovery_lookup_index()
used to be a part of vy_recovery_iterate_index() and was factored out
when index logging was moved to be called after WAL write, from
vy_index_commit_create(), because during recovery we need to check if an
index creation record was flushed to vylog before restart - currently we
do it by trying to look it up in the recovery context.

To stop using index lsn as vylog index id and remove lsn from index
options, I'm planning to make the function loading an index from vylog
advance an internal vylog counter so that the next time it is called it
loads a newer incarnation of the same index. vy_recovery_lookup_index()
doesn't fit this concept. So I introduce vy_recovery_load_index() that
calls vy_recovery_lookup_index() and vy_recovery_iterate_index()
internally and make the two functions private to vylog. To deal with
indexes not logged due to vylog errors, I introduce a per index flag,
vy_index->is_committed, which is set if the index record was flushed to
vylog - the same approach is already used to handle index drop (see
vy_index_commit_drop()).

Closes #2535

* Removed all functions and extensions that treat utf16 input
* Now only UTF-8 supported

Closes #2295

Now if a prepared transaction is aborted, it expects to be the
latest prepared TX in TX manager. It's not true in two cases:

- The transaction failed during preparation. The TX is in partially
  prepared state and must rollback all the changes it made in mems
  but the preparation was not finished and thus the TX could not be
  considered as the latest in TX manager.

- It's a cascading rollback with more than on TX. It would be
  graceful for the latest aborted TX to set the previous TX as
  the latest after the abortion. But the TX does not know the
  previous prepared TX and simply set to NULL appropriate pointer;
  when the time comes for the previous TX to be aborted it
  does not see itself as the latest.

The TX must not expect itself to be the latest but must handle
the last_prepared_tx pointer only if it is the latest.

Fix it and add tests.

Fix #2588 (case 1)
Fix #2591 (case 2)

Straightforward change to remove redundant `sql-` prefix
from tests in `sql` test suite.

Better safe than sorry.
@todo@: rewrite to send an error for reporting to iproto thread instead.

In scope of gh-2507.

Part of the #2507

Update for the hackish usage of space_def, update for
_trigger system space

Review fixes.
Part of #2435.

* better messages
* fold sql_prepare()
* rewrite the message decode

Add iproto_execute command to get not only sql rows as the result,
but also sql meta data about each result column.

Make SQLITE_LIMIT_VARIABLE_NUMBER be static

SQLITE_LIMIT_VARIABLE_NUMBER is the run time limit of the
variable count in the query. The Tarantool doesn't support dynamic
limits for such things. Let's make this limit be enum instead
of value in the limits array (struct sqlite3.aLimit).

Part of #2285.