Lua: updated for Lua5.3

Summary:
Add of:

- shebang
- hexadecimal float
- special char: \u{xxx}, \xXX, \ddd and `\z`
- bitwise operator
- metamethod
- some other improvements

Reviewers: dhaumann, #framework_syntax_highlighting

Reviewed By: dhaumann, #framework_syntax_highlighting

Subscribers: #frameworks

Tags: #framework_syntax_highlighting, #frameworks

Differential Revision: https://phabricator.kde.org/D12689