* struct stat_counter keeps all statistics data (supports several instances)
* test sends 100 rps, but this methods count only 80
* stat counting bug fixed
* style fixes
* renamed as stat.c to rmean.c

* msgpack encoding with lua c api(call, insert, eval, ping)
* remove extra hash lookup in net.box
* review fixes for netbox-write
* rewrite all encoding fucntions using Lua/C
* replace channels with fiber.sleep()/fiber.wakeup()
* review fixes (remove an unnecessary include)

This patch adds four new functions to API:

  * luaL_checkuint64()
  * luaL_touint64()
  * luaL_checkint64()
  * luaL_toint64()

This functions are needed to rewrite request encoding in net.box.

With structured configuration, i.e. a Lua table for a list of
replication peers, it is difficult to pass a configuration option
to the hook function as a single C object. Don't pass
options in, but query them from the hook function with cfg_get*
API.

As a result, all "change" hooks have the same signature now,
a step closer to the pluggable configuration API.

Introduce a layer of wrappers for a number of internal box functions,
dealing with accss to spaces and indexes.

These wrappers:
    * don't throw exceptions
    * have a common prefix box_
    * are exported in the server development headers

Rewrite Lua C bindings to use the public API described above.
Rewrite Lua FFI bindings to do the same.
Add test.

Conflicts:
	src/box/alter.cc
	test/app/snapshot.test.lua

* style fixes
* fix a bug in key opts decoder (alter.cc)
* ensure dimension is visible in box.space
* rebuild bootstrap.snap to use the new format

- fix net.box to satisfy strict.lua requirements
- after review fixes
- fix buffer:checksize() in buffer.lua

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()

- upsert semantics is update or insert, not "always update"
- upsert doesn't return tuple
- bind upsert as tuple method in Lua (useful for QA)
- ensure upsert is properly encoded in xlog

Implement a generic inter-cord communication bus and use it
in separating network I/O and transaction processor.

Split all request processing work into network thread part
and transaction processor thread part, and make these
parts multi-threading safe.

Generalize fiber pool into an own data structure and API.

Misc cleanups.

*) refactoring of update operation
*) added tests

Refactor iobuf and extract ibuf/obuf into small allocators
library.
Fix leaking obuf_destroy() (some slabs could be leaked by
destroy).

Introduce rename to follow the style of small allocators library.

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