QT4: scroll to playingItem when changing view

I think it works better thisway, but you're free to change it if you think
otherwise.

modules/gui/qt4/components/playlist/standardpanel.cpp

@@ -388,6 +388,7 @@ void StandardPLPanel::showView( int i_view )
     }
 
     browseInto();
+    gotoPlayingItem();
 }
 
 void StandardPLPanel::cycleViews()