in desktoptheme/widgets/panel-background.svg. Path is currently hard-coded.
Added programmer-art edition of panel-background.svg
TODO: Discuss with artists what they need from the code to get the
desired background look in the panel and how to manage different
backgrounds depending on where the panel is positioned.
* Horizontal panel layout now works
svn path=/trunk/KDE/kdebase/workspace/plasma/desktoptheme/; revision=707284
