title: Fragments onResume from back stack
body: <p>I'm using the compatibility package to use Fragments with Android 2.2. 
  When using fragments, and adding transitions between them to the backstack, I'd like to achieve the same behavior of onResume of an activity, i.e., whenever a fragment is brought to "foreground" (visible to the user) after poping out of the backstack, I'd like some kind of callback to be activated within the fragment (to perform certain changes on a shared UI resource, for instance).</p>
  
  <p>I saw that there is no built in callback within the fragment framework. is there s a good practice in order to achieve this?</p>