title: in ember v2 router why isn't controllerFor() giving a reference to this controller?
body: <p>Here's the fiddle.</p>
  
  <p><a href="http://jsfiddle.net/inconduit/hf7XM/10/" rel="nofollow">http://jsfiddle.net/inconduit/hf7XM/10/</a></p>
  
  <p>Steps to reproduce the issue: </p>
  
  <ul>
  <li>Click on 'Go to Posts'.  </li>
  <li>Click the 'controllerFor' text, it won't clear the list.  </li>
  <li>Click the global reference text, it will clear the list.</li>
  </ul>
  
  <p>It seems that the controller reference returned by <code>controllerFor()</code> is not actually the <code>PostsIndexController</code>?  Why is that?  </p>
  
  <p>I hacked it in the <code>setupController()</code> hook of the Route to set a global reference to that controller on App, and when I set the content on that reference to a new array in <code>emptyList2()</code>, the list correctly clears in the template.</p>
  
  <p>Am I using <code>controllerFor()</code> wrong? Or misunderstanding what it's returning? Is it a scoping issue?  Please help me out.</p>
  
  <pre><code>App.PostsIndexRoute = Ember.Route.extend({
    setupController : function(controller,model) {
      controller.set('content',['one','two','three']);
      App.postsIndexController = controller;
    }
  });
  
  // receives the {{action}} from the template
  App.PostsController = Ember.Controller.extend({
    emptyList : function() {
      this.controllerFor('postsIndex').set('content',Ember.A());
    },
    emptyList2 : function() {
      App.postsIndexController.set('content',Ember.A());
    }  
  });
  </code></pre>