macosx: Hide prefs window if application is inactive

Makes sure the prefs window does not stay on top and hides
all other applications if VLC is inactive.

modules/gui/macosx/prefs.m

@@ -179,6 +179,7 @@ static VLCPrefs *_o_sharedMainInstance = nil;
 
     if (!OSX_SNOW_LEOPARD)
         [o_prefs_window setCollectionBehavior: NSWindowCollectionBehaviorFullScreenAuxiliary];
+    [o_prefs_window setHidesOnDeactivate:YES];
 
     [self initStrings];
     [o_prefs_view setBorderType: NSGrooveBorder];

modules/gui/macosx/simple_prefs.m

@@ -229,6 +229,7 @@ static VLCSimplePrefs *_o_sharedInstance = nil;
 
     if (!OSX_SNOW_LEOPARD)
         [o_sprefs_win setCollectionBehavior: NSWindowCollectionBehaviorFullScreenAuxiliary];
+    [o_sprefs_win setHidesOnDeactivate:YES];
 
     [o_hotkeys_listbox setTarget:self];
     [o_hotkeys_listbox setDoubleAction:@selector(hotkeyTableDoubleClick:)];