fix(WebWorker): Fix Todo Server demo and add test to ensure the demo can bootstrap.

Closes #3970

modules/examples/src/web_workers/todo/index_common.ts

@@ -1,6 +1,4 @@
-import {NgFor} from 'angular2/src/core/directives/ng_for';
-import {View, Component} from 'angular2/src/core/metadata';
-import {FORM_DIRECTIVES} from 'angular2/src/forms/directives';
+import {NgFor, View, Component, FORM_DIRECTIVES} from 'angular2/web_worker/worker';
 import {Store, Todo, TodoFactory} from './services/TodoStore';
 
 @Component({selector: 'todo-app', viewBindings: [Store, TodoFactory]})

modules/examples/src/web_workers/todo/services/TodoStore.ts

@@ -1,4 +1,4 @@
-import {Injectable} from 'angular2/angular2';
+import {Injectable} from 'angular2/web_worker/worker';
 import {ListWrapper, Predicate} from 'angular2/src/core/facade/collection';
 
 // base model for RecordStore