title: CCMenuItemImage isn't showing the selected state
body: <p>The <a href="http://www.cocos2d-iphone.org/api-ref/0.9.0-beta/interface_c_c_menu_item_image.html" rel="nofollow">documentation for CCMenuItemImage</a> doesn't actually say what it does.</p>
  
  <p>There are quite a few subclass CCMenuItem.
  I've inherited a project that's using it as a button.</p>
  
  <pre><code>CCMenuItem *start;
  start = [CCMenuItemImage itemFromNormalImage:[self prefixedImage:@"start button.png"]
                                 selectedImage:[self prefixedImage:@"start button selected.png"]
                                        target:myTarget
                                      selector:@selector(start:)];
  </code></pre>
  
  <p>It <em>was</em> using the same button for both states.
  I modified it to have a different image for the selected state.</p>
  
  <p>I was expecting/hoping that when I touch the item it will be highlighted, and when I release the button it will send my target action (which it does).</p>
  
  <p>(aside: in iOS parlance, i <em>know</em> that <code>highlighted</code> and <code>selected</code> are two different things.  But this library does not seem to have that difference.)</p>
  
  <p>So:</p>
  
  <ul>
  <li>Is it intended to use this "menu item" as a button?</li>
  <li>When is the selected image of this menu item displayed?</li>
  <li>How should I go about making it display as selected?</li>
  </ul>