title: Open fragment from Preference fragment; Change action bar layout from nested Preference screen on Android
body: <ol>
  <li><p>I've got <code>PreferenceFragment</code> added in activity, so I see my preferences (and the most important I see my custom action bar). But this fragment has nested preference screens inside and when I click one of those then action bar is changed to default one (nested preference screen is probably new activity?).</p>
  <p>How can I remain with my custom set Action bar, please?</p>
  </li>
  <li><p>In that <code>PreferencesFragment</code> I need to have an &quot;About us&quot; button which shows some text (So probably show other framgent).</p>
  </li>
  </ol>