A couple of optimizations are done in this PR. One, we now will check config ahead of time to see if a module is disabled before running any module code. Also, we won't try to discover a git repository unless the module requests access to it.
Add a configuration option (show_sync_count) to the git_status module that will show/hide the counts ahead/behind of the tracked branch. Currently have this default to false, and would opt-in to show this information.
