title: Update value when value is selected in Ember.Select
body: <p>I have a Ember.Select in my template and an image:</p>
  
  <pre><code>Difficulty: {{view Ember.Select id="id_diff" contentBinding="difficulties" optionValuePath="content.id" optionLabelPath="content.title"}}
  &lt;img src="(path)" /&gt;
  </code></pre>
  
  <p>The Select is filled with values coming from server; in the controller:</p>
  
  <pre><code>difficulties: function() {
      return this.get('store').find('difficulty');
  }.property()
  </code></pre>
  
  <p>and the model:</p>
  
  <pre><code>Gmcontrolpanel.Difficulty = DS.Model.extend({
      title: DS.attr('string'),
      description: DS.attr('string'),
      path: DS.attr('string')
  });
  </code></pre>
  
  <p>And that's ok; but i would like that when a difficulty is selected from the Ember.Select, the corrispondent path property would be inserted in the img tag
  Anyone knows how to get this result?</p>