Qt4 - Fix the saving of the preferences to avoid inaccuracies between the panels.

Preferences for dummies ( #603 ) is now almost done in Qt4. Please test and review my commits.

modules/gui/qt4/dialogs/preferences.cpp

@@ -272,16 +272,20 @@ void PrefsDialog::save()
     config_SaveConfigFile( p_intf, NULL );
 
     /* Delete the other panel in order to force its reload after clicking
-       on apply - UGLY but will work for now. */
-    /* THIS CODE IS STILL WRONG, FIXME */
-    if( current_simple_panel  && current_simple_panel->isVisible() && advanced_panel )
+       on apply. In fact, if we don't do that, the preferences from the other
+       panels won't be accurate, so we would have to recreate the whole dialog,
+       and we don't want that.*/
+    if( small->isChecked() && advanced_panel )
     {
         delete advanced_panel;
         advanced_panel = NULL;
     }
-    if( advanced_panel && advanced_panel->isVisible() && current_simple_panel  )
+    if( all->isChecked() && current_simple_panel  )
     {
-        delete current_simple_panel;
+        for( int i = 0 ; i< SPrefsMax; i++ )
+        {
+            if( simple_panels[i] ) delete simple_panels[i];
+        }
         current_simple_panel  = NULL;
     }