chore(test.typings): instrument against examples folder

chore(typing_spec): delete unused typing_spec files

Closes #7743

modules/angular2/examples/facade/ts/async/observable.ts

@@ -4,5 +4,5 @@ var obs = new Observable<number>((obs: Subscriber<number>) => {
   var i = 0;
   setInterval(() => { obs.next(++i); }, 1000);
 });
-obs.subscribe((i) => console.log(`${i} seconds elapsed`));
+obs.subscribe(i => console.log(`${i} seconds elapsed`));
 // #enddocregion