bps_tree: fixed balance and add more tests
Merge branch 'master' of https://github.com/tarantool/tarantool
fixed code style and added one more check to bps_tree
Add touch in cmake to exclude rerun ragel. closes #321
Merge branch 'master' of github.com:tarantool/tarantool
added tree iterator invalidation test
Merge branch 'master' of https://github.com/tarantool/tarantool
Remove 'box' prefix from module names

All bultin modules can be loaded with require('modulename')
instead of require('box.modulename')

Other changes:

 * _G.box is not initialized from tarantool_lua_init() anymore
 * box.info, box.stat, box.snapshot moved to src/box/lua
 * box.coredump() => coredump()
 * box.xxx = require('box.xxx') removed from tests
Merge branch 'master' into gh126-logging

Conflicts:
	src/lua/init.cc