box.ipc: add :close method. #158

+ use luaL_ref/luaL_unref to store lua scalar instead lua metatable.
+ add :is_closed method.
158-box.ipc.close: minor changes (code style)
Allow fiber:resume() and fiber:cancel() syntax in Lua bindings

Closes #161
Fix net_sql.mysql.test
remove unused malloc.h include (fix FreeBSD build)
update submodule
MMerge branch '158-box.ipc.close' into stable

Conflicts:
	doc/user/stored-procedures.xml
Merge branch 'stable' of github.com:tarantool/tarantool into stable
introduce direct library dependency to fix make -j8
added openmp sort for avl tree index initialization
Add tests for box.net.box race condition.

 + memory leak in box.net.box (timeouted responses)
 + remote:ping() never throw exception
update submodule
New Debian snapshot.
Add conflict/replaces tags for -module packages.
Update debian policy Standards-Version.
Update debian/copyright: base64.*.
Merge remote-tracking branch 'origin/openmp-avl-tree-index-sort' into stable
Ignore _text/download.md
fixed include paths in avl unit test
Merge remote-tracking branch 'origin/openmp-avl-tree-index-sort' into stable