chore(main): add isDefined alias for angular.isDefined

Author: ajoslin

js/angular/main.js

@@ -1,5 +1,7 @@
 var IonicModule = angular.module('ionic', ['ngAnimate', 'ngSanitize', 'ui.router']),
   extend = angular.extend,
   forEach = angular.forEach,
+  isDefined = angular.isDefined,
   isString = angular.isString,
   jqLite = angular.element;
+