OTHER: Add SkinManager class

Now Skin no longer is a singleton class.
In the long run, Skin will only hold information about a skin, while
SkinManager will be responsible for loading skins and notifying the windows
of the change

src/mainwindow/mainwindow.cpp

@@ -1,7 +1,7 @@
 /**
  *  This file is a part of Promoe, an XMMS2 Client.
  *
- *  Copyright (C) 2005-2008 XMMS2 Team
+ *  Copyright (C) 2005-2010 XMMS2 Team
  *
  *  This program is free software; you can redistribute it and/or modify
  *  it under the terms of the GNU General Public License as published by
@@ -28,6 +28,7 @@
 #include "shadeddisplay.h"
 #include "equalizerwindow.h"
 #include "Skin.h"
+#include "skinmanager.h"
 
 #include <QSettings>
 #include <QIcon>
@@ -102,7 +103,8 @@ MainWindow::MainWindow (QWidget *parent) : BaseWindow (parent)
 
 MainWindow::~MainWindow ()
 {
-	delete Skin::getInstance ();
+	//FIXME: This should perhaps go somewhere else
+	delete SkinManager::instance ();
 }
 
 void