refactor(async): use ultralight Observable

Closes #5283

modules/angular2/test/public_api_spec.ts

@@ -686,51 +686,9 @@ var NG_ALL = [
   /*
    RxJS API - may need to maintain as RxJS evolves
   */
-  'EventEmitter.mapTo():js',
-  'EventEmitter.next():js',
   'EventEmitter.emit():js',
-  'EventEmitter.materialize():js',
-  'EventEmitter.merge():js',
-  'EventEmitter.mergeAll():js',
-  'EventEmitter.mergeMap():js',
-  'EventEmitter.mergeMapTo():js',
-  'EventEmitter.multicast():js',
-  'EventEmitter.observeOn():js',
-  'EventEmitter.remove():js',
-  'EventEmitter.repeat():js',
-  'EventEmitter.retry():js',
-  'EventEmitter.retryWhen():js',
-  'EventEmitter.throttle():js',
-  'EventEmitter.toPromise():js',
-  'EventEmitter.window():js',
-  'EventEmitter.windowCount():js',
-  'EventEmitter.windowTime():js',
-  'EventEmitter.windowToggle():js',
-  'EventEmitter.windowWhen():js',
-  'EventEmitter.withLatestFrom():js',
-  'EventEmitter.zip():js',
-  'EventEmitter.zipAll():js',
-
   'Observable:js',
-  'Observable#combineLatest():js',
-  'Observable#concat():js',
   'Observable#create():js',
-  'Observable#defer():js',
-  'Observable#empty():js',
-  'Observable#forkJoin():js',
-  'Observable#from():js',
-  'Observable#fromArray():js',
-  'Observable#fromEvent():js',
-  'Observable#fromEventPattern():js',
-  'Observable#fromPromise():js',
-  'Observable#interval():js',
-  'Observable#merge():js',
-  'Observable#never():js',
-  'Observable#of():js',
-  'Observable#range():js',
-  'Observable#throw():js',
-  'Observable#timer():js',
-  'Observable#zip():js',
   'Observable.buffer():js',
   'Observable.bufferCount():js',
   'Observable.bufferTime():js',