what to do with xfdesktop

[Jasper Huijsmans]

Ok, I put the desktop window back in CVS. I did some code reordering
along the way as well.

Xfdesktop now sets an XFCE_DESKTOP_WINDOW property on the root window to
hold the window id.

The dialog (still) has the option to not set the background. I probably
will replace it with an option to run an external program.

I could get immagick to set the background by using 

 $ display -window <id> <image>

Unfortunately this was the only program I could find that actually
supports a different window id.

I tried to get xplanet to work with the -vroot option, but that didn't
work, perhaps I can still find out later.

	Jasper