Previously to 4722496292 ("Remove gnome-boxes from default GNOME apps."), USB
redirection for GNOME Boxes had been working out-of-the-box. Reinstate the
extensions that made that possible, so that simply adding the gnome-boxes
package back to one of the gnome-desktop-configuration fields does the right
thing.
* gnu/services/desktop.scm (gnome-setuid-programs): New procedure.
(gnome-desktop-service-type) [privileged-program-service-type]: Use it as an
extension.
* gnu/packages/gnome.scm (gnome-boxes):
[inputs]: Move spice-gtk to...
[propagated-inputs]: ... here.
[description]: Document extra steps necessary to enable the USB redirection
feature.
Change-Id: If84e8a2e0c480ddd1d7cd294890fad1ae2a76987
Reviewed-by: Liliana Marie Prikler <liliana.prikler@gmail.com>