ng-class support for Surfaces :smile:

As promised, ng-class support for Surfaces.

Adds a safe method to $famous for getting isolate from a scope. It uses the $delegateProvider so that anything in the $animate.addClass/$animate.removeClass/$animate.setClass pipeline, which is used by directives like ng-class, ng-class-odd, ng-animate, etc., will get the classes set by these actions on the underlying Surface...so long as the renderNode for the scope isolate *is* a Surface.