* Remove the GDM3 settings, since the configuration format for GDM
change again, yay.
* Add a dconf file for the new-style GDM3 configuration.
* Add a XML file describing the available resolutions for the
background (for use with GNOME).
* postinst: use a higher priority for the 1920x1080 background.
* Cleanup postinst/prerm/postrm.
* Add a new alternative: desktop-background.xml.
* Use it from the gsettings override.
* Reload gdm3 after installation/removal.
* Drop old libgnome2-common hack.
* Clean up an alternative that is no longer available.
Josselin Mouette
Paul Tagliamonte
Yves-Alexis Perez