Rewrite HashIndex using tuple_compare
Allow multipart hash in config checks (blueprint multipart-hash)
Add multipart hash tests
Add tests for search in NUM64 HashIndex using NUM key
tuple-compare-hash: review fixes

- simplify the comparison function, only shortuct the single-part
  NUM key case.
- tweak mh_find() declaration
- remove wrappers around hash values
  and keys
Merge branch 'tuple-compare-hash'
Add tests for multipart HASH indexes.

Derive some tests for multipart HASH indexes
from the original implementation by A. Demakov
before dropping the branch.
Document that HASH indexes can be multi-part now.
Changes:
* 	Implementing LUA printer (https://blueprints.launchpad.net/tarantool/+spec/tc-lua-printer)
* 	Moving xlog printer code into tc_print_xlog.{c,h}, leaving basic printing code in tc_print.{c,h}.
* 	Fix TC bug (https://bugs.launchpad.net/tarantool/+bug/1185746), Added support for snap print formatters.
* 	Added temporary workaround for option (-B or --bin), that allow you to print STR instead of INT and INT64 in lua formatter.
	Works in "keys" and UPDATE (ASSIGN or INSERT).
*	Fix of stdin: add custom function for pipe instead of stdin (very slow with readline)
*	Fix for realloc problems
	1) 	if size is 0, then behaviour is undefined
	2) 	in C99 if realloc returns NULL, and size is not zero (errno == ENOMEM) input buffer of memory is needed to be freed manually.
		Whitepaper of POSIX standart:
		http://pubs.opengroup.org/onlinepubs/9699919799/functions/realloc.html
*	Add support of -D (--delim) argument, that sets delimiter on start of tarantool client.
	Also, if you "cat" .snap or .xlog files in LUA format it prints delim in end of every coomand.
Remove CheckBuiltInFunctionExists logic from CMake
Add an error message about GCC 4.7 and libobjc2 to CMake
Fix warnings detected by clang
Fix ObjC Clang build broken by 13054aaa46d3c1db7263c449d085c87156fd86ea
Merge remote-tracking branch 'origin/stable'

Conflicts:
	third_party/luajit
Merge remote-tracking branch 'origin/stable' into stable
Merge branch 'stable'

Conflicts:
	cmake/compiler.cmake
	include/sio.h
	src/box/bitset_index.cc
	src/box/box_lua.cc
	src/lua/init.cc
	src/lua/session.cc
	src/sio.cc
	test/unit/objc_catchcxx.m
	third_party/luajit
fix travis (set git clone depth)
Merge branch 'master' into lua-types
lua-field: code review