Merge branch 'stable' into avl-tree-index

CMakeLists.txt

cfg/core_cfg.cfg_tmpl

cfg/tarantool_box_cfg.c

cfg/tarantool_box_cfg.h

client/tarantool/tc_print_xlog.c

client/tarantool/tc_query.c

doc/user/configuration-reference.xml

doc/user/errcode.xml

doc/user/lua-tutorial.xml

doc/user/persistence-architecture.xml

doc/user/plugins.xml

doc/user/server-administration.xml

doc/user/stored-procedures.xml

doc/user/tnt.css

doc/user/tutorial.xml

extra/rpm.spec.in

include/say.h

src/exception.cc

src/salloc.cc

src/say.cc