Log Message:
Update lang/lua53 to version 5.3.4.

Lua 5.3.4 fixes all bugs listed in
        http://www.lua.org/bugs.html#5.3.3

1. Expression list with four or more expressions in a 'for' loop can crash
   the interpreter.
   reported by Marco Scho:pl on 17 Jun 2016. existed since 5.2. fixed in 5.3.4.

2. Checking a format for os.date may read pass the format string.
   reported by Nagaev Boris on 10 Jul 2016. existed since 5.3.3. fixed in 5.3.4.

3. Lua can generate wrong code in functions with too many constants.
   reported by Marco Scho:pl on 17 Jul 2016. existed since 5.3.3. fixed in 5.3.4.

4. When a coroutine tries to resume a non-suspended coroutine, it can do some
   mess (and break C assertions) before detecting the error.
   reported by Marco Scho:pl on 20 Jul 2016. fixed in 5.3.4.

Lua 5.3.4 also contains several internal improvements and
includes a revised reference manual:
	http://www.lua.org/manual/5.3/