Conflicts:
	doc/sphinx/book/box/box_introspection.rst

Chagne iobuf to use slab_cache directly, bypassing an intermediate
allocation layer - this is necessry to make iobuf multi-threading
safe.

Introduce mpstream API to lua-msgpack encoder, which allows it
to encode msgpack into any memory source. The streaming API
should make it possible to encode even directly to network.

Patch region allocator to support the new API.
Patch iobuf/obuf output buffer of iproto to support the new API.

Extract Exception::clear(), Exception::move(), fiber()->exception
into struct diag methods. This refactoring makes desired logic
to be more clear.

Conflicts:
	src/iproto_port.cc

*) fixed potentionally unsafe code:
  on memory fail there could be port->found > 0 and uninitialized port->svp

 on memory fail there could be port->reply.found > 0 and uninitialized port->svp,
 that could lead to random error after svp restoration.
*) possibly fixed OPENTAR-97

finalizers.test marked as long run in suite

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

test-run udpated

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

closes gh-856

Conflicts:
	include/fiber.h
	include/mutex.h
	src/admin.cc
	src/admin.rl
	src/box/box_lua.cc
	src/box/request.cc
	src/box/txn.cc
	src/coeio.cc
	src/coio.cc
	src/fiber.cc
	src/ipc.cc
	src/iproto.cc
	src/log_io.cc
	src/lua/bsdsocket.cc
	src/lua/init.cc
	src/lua/session.cc
	src/memcached-grammar.cc
	src/memcached-grammar.rl
	src/memcached.cc
	src/recovery.cc
	src/replica.cc
	src/replication.cc
	src/say.cc
	src/session.cc
	src/tarantool.cc
	src/util.cc

Rename global `fiber` into `fiber_ptr`

Rename global `fiber` into `fiber_ptr` (for use with gdb and avoidance of ambiguity with `struct fiber`)

1. Enable background=false for test-run
2. Check local directory for config

- encapsulate iproto configuration into iproto module API
- iobuf: change the module to be thread-safe.
- iobuf: rename obuf_ensure() to obuf_reserve() as is conventional
  with the reset of API.
- iobuf: change ibuf to use slab cache directly, bypassing the region allocator
- iobuf: consistently use int for obuf/obuf_svp iov pos and obuf_iovcnt
- iobuf: remove iobuf_flush
- iobuf: add iobuf pin/unpin API in preparation for iproto-in-a-thread
- iobuf: don't trust iov_len as an end marker in obuf_reset()
  There is a chance (although currently it's never used) that one of the
  vectors is allocated, but not used, and the next vector of a larger size
  is used. In that case reset loop may stop prematurely.

Conflicts:
	src/module/mysql/mysql.cc
	test/module/net_sql.mysql.result
	test/module/net_sql.mysql.test

Backport fix from tarantool/mysql by Anton Reznikov