Set oxygen as kwin decoration default plugin

svn path=/trunk/KDE/kdebase/workspace/; revision=732861

plugins.cpp

@@ -23,7 +23,7 @@ PluginMgr::PluginMgr()
     : KDecorationPlugins( KGlobal::config())
     {
     defaultPlugin = (QPixmap::defaultDepth() > 8) ?
-            "kwin3_plastik" : "kwin3_quartz";
+            "kwin3_oxygen" : "kwin3_plastik";
     loadPlugin( "" ); // load the plugin specified in cfg file
     }