cleanup(testing): create top level files for mocks

Closes #5381

modules/angular2/testing.ts

@@ -14,3 +14,9 @@ export {
 } from './src/testing/test_component_builder';
 export * from './src/testing/test_injector';
 export * from './src/testing/fake_async';
+
+export {MockViewResolver} from 'angular2/src/mock/view_resolver_mock';
+export {MockXHR} from 'angular2/src/compiler/xhr_mock';
+export {MockNgZone} from 'angular2/src/mock/ng_zone_mock';
+export {MockApplicationRef} from 'angular2/src/mock/mock_application_ref';
+export {MockDirectiveResolver} from 'angular2/src/mock/directive_resolver_mock';