added version control to lua iterators
fixed comment
consistent use of docbook userinput tag
socket.tcp_server method #450.
Merge branch 'stable', closes #450

Conflicts:
	src/lua/bsdsocket.lua
	test/box/bsdsocket.result
	test/box/bsdsocket.test
all socket methods are defined equally #450
Merge branch 'master' of https://github.com/tarantool/tarantool
replication.xml changes
Merge remote-tracking branch 'origin/add-iterator-version-control-v2'
tcp_server: call prepare function before bind

(so user can use 'SO_REUSEADDR' option in tcp_server)
Merge branch 'stable'
Post-merge fixes
Merge branch 'master' of https://github.com/tarantool/tarantool
Drop out old sockets.
Fix gh-432: Sophia: ignored limit
Merge branch 'master' of github.com:tarantool/tarantool into snapshot_daemon
Drop snap_check_period (uses snapshot_period/10).

* Rename snap_period and snap_count to snapshot_period, snapshot_count.
* Move snap_daemon to box.internal