Add support for Lua 5.2 syntax

[JohnnyMorganz]

This is a tracking issue in relation to support for formatting Lua 5.2 syntax.

Note: support for Lua 5.2 syntax is dependent on support being provided by full-moon, the syntax parser used.

Syntax

• Goto and label statements
• String hex escapes and \z (Fix string escapes being incorrectly removed #91): Note, support for \z and strings taking multiple lines is currently not provided in full-moon.

If there is any other syntax currently missing from the above list, please comment and let me know

[LastTalon]

I believe 5.2 added \z and hex escapes as well as hex floats.