title: itemController in ArrayController vs #each
body: <p>Following along with the <a href="http://emberjs.com/guides/getting-started/display-a-button-to-remove-completed-todos/" rel="noreferrer">Getting Started Guide</a> I have this <a href="http://jsbin.com/enutit/2/edit" rel="noreferrer">http://jsbin.com/enutit/2/edit</a></p>
  
  <p>My question is how come I can't remove the itemController from this each helper</p>
  
  <pre><code>&lt;ul id="todo-list"&gt;
      {{#each controller itemController="todo"}}
          &lt;li {{bindAttr class="isCompleted:completed isEditing:editing"}}&gt;
  </code></pre>
  
  <p>and then add </p>
  
  <pre><code>itemController: 'todo',
  </code></pre>
  
  <p>to Todos.TodosController and have it work?</p>