feat(core): add support for ambient directives

Ambient directives can be configured when bootstraping an application.
Ambient directives can be used in every component of the application without
needing to explicitly list them.

modules/angular2/src/testing/test_injector.ts

@@ -1,5 +1,4 @@
 import {provide, Provider} from 'angular2/src/core/di';
-import {DEFAULT_PIPES} from 'angular2/src/core/pipes';
 import {AnimationBuilder} from 'angular2/src/animate/animation_builder';
 import {MockAnimationBuilder} from 'angular2/src/mock/animation_builder_mock';
 
@@ -107,7 +106,6 @@ function _getAppBindings() {
     ProtoViewFactory,
     provide(DirectiveResolver, {useClass: MockDirectiveResolver}),
     provide(ViewResolver, {useClass: MockViewResolver}),
-    DEFAULT_PIPES,
     provide(IterableDiffers, {useValue: defaultIterableDiffers}),
     provide(KeyValueDiffers, {useValue: defaultKeyValueDiffers}),
     Log,