Reflect in slab stats the quota size and index memory statistics.

arena_used_ratio - how much of arena is used
items_used_ratio - how much memory is actualy used for items,
given that there is some fragmentation. Doesn't reflect index pages
arena_used - how much of the quota is used (i.e. how much memory
is used for index and tuple data)
arena_size  - this is the same as box.cfg.slab_alloc_arena.
quota_size - how much of the quota is defined (box.cfg.slab_alloc_arena)
quota_used - how much of the quota is used (reflects the memory taken
by all slabs, including slabs in caches)

Incompatible change:
Extract detailed slab statistics to a separate call, box.slab.stats()

1)removed atfork xlog resources freeing - they could be corrupted but xlog thread
2)snapshot.test now use pcall(box.snapshot) for deterministic code flow

Iproto + wal permission test case
Wal writer bug fix port from 1.6.6

remove unused config

fixed gh-731 : now every rtree has it's own matras instance that is destroyed with rtree, releasing all memory of tree instance

gh-613 replication conflict test cases

gh-613 after review fixes

microsleep for CRDT test case, test-run updated

CRDT fix

- add a test case for authentication trigger
- pass user name to the trigger
- invoke trigger before the current user has been changed
- after review fixes

Implement basic support for stored functions in C/C++.

- split away struct func from struct func_def (function
object and function definition object).
- extend box.schema.func.create() to accept 'language' argument.
- move module API related cmake magic to its own file
- add test/lib to gitignore
- update to the new test-run
- add a test

* FreeBSD pthread_self() does not return int by pthread_self() becuseit has changed to pthread_getthreadid_np()
* Updated build information on FreeBSD 10.1

added additional checks to /wal_off/snapshot_stress.test.lua

Replace socket('AF_UNIX', 'SOCK_STREAM', 'ip') with
        socket('AF_UNIX', 'SOCK_STREAM', 0).

Fixes distributions with missing "ip 0 IP" line in /etc/protocols
(e.g. Arch Linux).

Test case

*)added proper cleanup
*)minor fixes and checks

finalizers.test marked as long run in suite

 *) added stress test for snapshotting
 *) moved finalizers.test.py to long_run

set test-run module in gh-3 branch for review

closes gh-856

Backport fix from tarantool/mysql by Anton Reznikov

Implement box.once().

Right now there is a race in box.once(), this is somethign we'll
need to fix when we have master election on simultaneous bootstrap.

The patch merely "establishes" the syntax which is going to work
most of the time.

Don't log exceptions of dead joinable fibers - it will
be logged by the caller, so avoid double logging.

recover_remaining_wals() is now more like an iterator,
vclockset_match() is only called when there is no current WAL.

Add a test case for gaps in LSNs.

Add a directory watcher, in addition to the file watcher.

Chagne wal_dir_rescan_delay default value to 2, since now it's
merely a backup.

Fix a crash in rollbackStatement() when rolling back a
statement trying to access a non-exissting space.

space_cache_find() is called before txn_begin_stmt(), thus
there is no statement object, nothing to roll back.

Remove iditioc tests from the suite.

Change the logic of recovery_finalize() to open
the next xlog if the last xlog had zero rows.
Add a test case.

Remove recovery->finalize, use recovery->writer instead.