Merge remote-tracking branch 'origin/master' into 1.6

doc/sphinx/book/administration.rst

doc/sphinx/book/app_c_lua_tutorial.rst

doc/sphinx/book/app_d_plugins.rst

doc/sphinx/book/box/box_index.rst

doc/sphinx/book/box/box_space.rst

doc/sphinx/book/box/box_tuple.rst

doc/sphinx/book/box/net_box.rst

doc/sphinx/book/box/triggers.rst

doc/sphinx/reference/console.rst

doc/sphinx/reference/csv.rst

doc/sphinx/reference/digest.rst

doc/sphinx/reference/fiber.rst

doc/sphinx/reference/fio.rst

doc/sphinx/reference/other.rst

doc/sphinx/reference/pickle.rst

doc/sphinx/reference/shard.rst

doc/sphinx/reference/socket.rst