Capture defp? as meta to get different coloring

Capture `def` and `defp` as meta in the language syntax to get different coloring. This is consistent with
how other languages such as Erlang and Python for instance color function names in their definition blocks in Sublime.

Note: I'm using a rather simplistic theme, so this might/might not affect other people.
Well I'm just getting started with Elixir. I don't know all the language constructs yet. (:
But I was having a hard time time glancing at a source file and quickly identifying the key components, such as functions, since they weren't colored properly. 

Would adding the mentioned language constructs to the syntax file as metas be worthy of another pull request then? Or I shouldn't even bother?