Allow for manual scope updating

I have tags that are asynch loaded from an api with each character typed into the input. With the change proposed I can now update the scope manually through a change event.  The $render method is presently type casting any object created to a string.  The change I have proposed gets around this by skipping the $render method if the current and old model differ by type.  The controller.$render should eventually be refactored to handle various data types.