Extendable StarlingMediatorMap and Integrated fix from robotlegs/robotlegs-framework#25

1: Made the StarlingMediatorMap much easier to extend in that you can create a derivative class that can override the addView/removeView methods easily.

2: Integrated robotlegs/robotlegs-framework#25 fix
I was getting the same kind of injector warnings that were happening in robotlegs/robotlegs-framework#25 and I noticed that the StarlingMediatorMap code in robotlegs-starling-plugin did not have the changes made for this, so I added those extra checks.