Fix for scaled images. Request to break freeze.

[Jasper Huijsmans]

Alright, this is my proposed solution for the scaled icon problems. Both
libxfcegui4 and xfce4-panel were changed to get the desired behaviour. 

http://members.home.nl/xfce4/files/libxfcegui4-test.tar.bz2

http://members.home.nl/xfce4/files/xfce4-panel-test.tar.bz2


It works for me and Francois, so it has been 'tested' ;-), but perhaps
someone else who currently is seeing problems with icon scaling could
give it a try. I'm still not sure if we should put it in before 4.0.

	Jasper