multi-resolution backgrounds

[Matthias Clasen]

Hey,

for a long time now, we've had the problem that we need to install
multiple versions of the default background (regular, wide, dual-screen,
etc), and leave the user to pick the best one manually. 

I finally sat down and finished a patch the I had lying around to make
the gnome desktop support multi-resolution images. It piggybacks on
Soerens animated background work and lets you specify backgrounds like
this:

<background>
  <static>
    <duration>10000</duration>
    <sizes>
      <file width="800" height="600">background-small.png</file>
      <file width="1600" height="1200">background-medium.png</file>
      <file width="1920" height="1200">background-huge.png</file>
    </sizes>
  </static>
</background>

This will show up as a single entry in the appearance capplet, and
nautilus will pick the best size depending on the screen resolution.

I hope to get this into F9 soon, for now, you'll have to use the
patch in http://bugzilla.gnome.org/show_bug.cgi?id=510554


Matthias