Add `goto` statement as reserved keyword with Lua 5.2

[Roland]

@lua4web said on 2013-10-05 20:14:

Hello!
This is nice, I like the possibility to declare globals if necessary.
BTW, in Lua 5.2 there is goto keyword, so it's better to add

if _VERSION:match('5.2') then luaKeyword['goto'] = true end

somewhere.
Peter