feature(core): update RxJS to 5.0.0-beta.11 (#10648)

modules/@angular/examples/facade/ts/async/observable.ts

@@ -7,7 +7,9 @@
  */
 
 // #docregion Observable
-import {Observable, Subscriber} from 'rxjs/Rx';
+import {Observable} from 'rxjs/Observable';
+import {Subscriber} from 'rxjs/Subscriber';
+
 var obs = new Observable<number>((obs: Subscriber<number>) => {
   var i = 0;
   setInterval(() => { obs.next(++i); }, 1000);