QT4: compare also screengeometry to see if screenresolution has changed

 when checking if fullscreencontrollers position needs to be
 recalculated. Should fix #2283 (what I understand that ticket)

 Please review and test.

modules/gui/qt4/components/controller.cpp

@@ -699,11 +699,12 @@ void FullscreenControllerWidget::showFSC()
     adjustSize();
     /* center down */
     int number = QApplication::desktop()->screenNumber( p_intf->p_sys->p_mi );
-    if( number != i_screennumber )
+    if( number != i_screennumber ||
+        screenRes != QApplication::desktop()->screenGeometry(number) )
     {
+        screenRes = QApplication::desktop()->screenGeometry(number);
         msg_Dbg( p_intf, "Calculation fullscreen controllers center");
         /* screen has changed, calculate new position */
-        QRect screenRes = QApplication::desktop()->screenGeometry(number);
         QPoint pos = QPoint( screenRes.x() + (screenRes.width() / 2) - (width() / 2),
                              screenRes.y() + screenRes.height() - height());
         move( pos );

modules/gui/qt4/components/controller.hpp

@@ -264,6 +264,7 @@ private:
     int i_mouse_last_x, i_mouse_last_y;
     bool b_mouse_over;
     int i_screennumber;
+    QRect screenRes;
 
 #ifdef WIN32TRICK
     bool b_fscHidden;