Merge remote-tracking branch 'origin/master' into fix-gh-498

doc/user/configuration-reference.xml

doc/user/databases.xml

doc/user/replication.xml

doc/user/stored-procedures.xml

doc/www/pelicanconf.py

extra/dist/dist.lua

src/box/access.h

src/box/box.cc

src/box/box.h

src/box/cluster.cc

src/box/engine_memtx.cc

src/box/engine_sophia.cc

src/box/hash_index.cc

src/box/lua/info.cc

src/box/lua/load_cfg.lua

src/box/lua/schema.lua

src/box/lua/snapshot_daemon.lua

src/box/lua/tuple.cc

src/box/lua/tuple.lua

src/box/recovery.cc