Finished up autocomplete_sources action and added frontend to fetch data only when its needed

Added wait_for_ajax to specs

Fixed builds and improved the setup/destroy lifecycle

Changed global namespace and DRYed up loading logic

Added safety for accidentally loading data twice

Removed destroy as its not necessary and is messing with click events from a blur race condition

Created AutocompleteSourcesController and updated routes

Fixed @undefined from tabbing before load ends

Disable tabSelectsMatch until we have loaded data

Review changes

Moved most of the functions that contained "window.doSomething" that were located at:
- app/assets/javascripts/application.js
To the following file:
- app/assets/javascripts/lib/utils/common_utils.js

The functions listed here:
- window.ajaxGet
- window.split
- window.extractLast
- window.rstrip
- window.disableButtonIfEmptyField
- window.disableButtonIfAnyEmptyField
- window.sanitize
- window.unbindEvents
- window.shiftWindow

Now will be accessible from the "gl.utils" namespace

Updated other tests