Multi-directive approach with ng-model integration and event handling.

Moving to directives that integrate with ng-model so that we can use AngularJS bidirectional binding and do event handling within the AngularJS lifecycle. The directives are no longer using kendo.bind/kendo.init and do not rely on the use of kendo observables.

Moving code from my [plunker](http://plnkr.co/edit/rPZMAcBJvNV3tqD6rUg2?p=preview)