feat(build): require parameter types

Fixes #2833

modules/angular2/src/router/location.ts

@@ -72,7 +72,8 @@ export class Location {
 
   back(): void { this._platformStrategy.back(); }
 
-  subscribe(onNext, onThrow = null, onReturn = null): void {
+  subscribe(onNext: (value: any) => void, onThrow: (exception: any) => void = null,
+            onReturn: () => void = null): void {
     ObservableWrapper.subscribe(this._subject, onNext, onThrow, onReturn);
   }
 }