title: Why can't I set a layout for a page in a QStackedWidget in designer?
body: <p>Steps to reproduce in designer for Qt 4.8.0</p>
  
  <ul>
  <li>I create a new dialog form in Qt Designer</li>
  <li>I add a QStackedWidget to the dialog</li>
  <li>I set the layout of the dialog to make the stacked layout size with the dialog</li>
  <li>I add a few controls to page one in the stacked widget</li>
  <li>I select the first page in the stacked widget in the right hand tree view of controls</li>
  <li>The icon next to that page (which is a QWidget) shows the page is missing a layout</li>
  </ul>
  
  <p>When I click one of the layout buttons above, it doesn't change the layout of the page QWidget, it changes the layout of the dialog even though I had explicitly selected the page.</p>
  
  <p>Is this a bug in designer? Am I missing something? I really don't want to add the layouts programatically as that prevents me from being able to layout the pages in designer in the same .ui file</p>