Moved positions and sizes of close and shade buttons to Skin
changed buttons to use PixmapButton
moved buttons from PlaylistWindow to PlaylistWidget and PlaylistShade
removed now unused Button
fixed position of shadebutton (was off by 1)
fixed icon of shade button in shaded mode
Use PixmapButton in most cases insteas of Button or ToggleButton
Moved positions and sizes of the buttons to Skin and let it return QIcons instead of Pixmaps