Adding GLExtension files and getting ready to make the port over to new repo.

Change-Id: I8a7d5eeb0a7787bfc6c5bffc6ed0239d8b8f45a3
Reviewed-on: http://www.matthewh.me/gerrit/2
Reviewed-by: Matthew Hoggan <matthew.hoggan@matthewh.me>
Tested-by: Matthew Hoggan <matthew.hoggan@matthewh.me>