title: Clear back stack using fragments
body: <p>I ported my Android app to honeycomb and I did a big refactor in order to use fragments. In my previous version, when I pressed the Home button I used to do a <code>ACTIVITY_CLEAR_TOP</code> in order to reset the back stack. </p>
  
  <p>Now my app is just a single Activity with multiple fragments, so when I press the Home button I just replace one of the fragments inside it. How can I clear my back stack without having to use <code>startActivity</code> with the <code>ACTIVITY_CLEAR_TOP</code> flag? </p>