feat(core): Add QueryList#forEach

modules/angular2/src/core/linker/query_list.ts

@@ -51,6 +51,11 @@ export class QueryList<T> {
    */
   reduce<U>(fn: (acc: U, item: T) => U, init: U): U { return this._results.reduce(fn, init); }
 
+  /**
+   * executes function for each element in a query.
+   */
+  forEach(fn: (item: T) => void): void { this._results.forEach(fn); }
+
   /**
    * converts QueryList into an array
    */