Conflicts:
	doc/user/configuration-reference.xml
	doc/user/persistence-architecture.xml
	doc/user/stored-procedures.xml

Conflicts:
	test/lib/tarantool_server.py
	test/lib/test_suite.py
	test/lib/unittest_server.py

misc cleanup

Because of v2->v3 migration mess different systems have different python
set by default. It is recommended to use versioned binaries.

Signed-off-by: Anatol Pomozov <anatol.pomozov@gmail.com>

Signed-off-by: Anatol Pomozov <anatol.pomozov@gmail.com>

Fixes gh-153.

-related distributions due to libbfd crash

This patch limits range of numbers that pushed as lua_Integer to
[INT32_MIN, INT32_MAX].

Conflicts:
	client/tarantool/tc_cli.c

Use common context for lua reference and for trigger state.
Wrap all calls to lua_call into a try/catch block.
Introduce LuarefGuard
Remove box_luactx, it's not adding any value now.
Implement multiple triggers. Reuse code in lua/trigger.cc.
Misc cleanups.
Rename a few files.

on_replace triggers on struct lua_trigger.
Session and space triggers use the same technology.
Code cleanup.

Miscallenous cleanups and refactoring.

Add comments to trigger.h
Implement LuarefGuard - a stack object to automatically
release a Lua reference on return or exception.

Add more context to struct trigger and get rid of specialized
objects in alter.cc.

Add optional 'destroy' to struct trigger, which is required
in space-luatriggers.

msgpuck is an external project and hosts its headers within
the same directory which contains its C files.

Therefore, for msgpuck, we have to add src/lib to the header search path,
whether we want it or not.

Since it's there anyway, kill include/lib and move all
headers of all other stand-alone libraries to their respective
directories in lib/.

include_directories(src/) is a total blasphemy, and is thus
removed.