Require latest gtk+ and libvirt-glib
Require latest gtk+ and libvirt-glib

- Several people have reported that boxes simply don't work against
  slightly older gtk+ and we know for a fact that UI doesn't look good
  against gtk+ < 0.3.3.
- Latest libvirt-glib is required for domain reconfiguration API, which we
  use now.

https://bugzilla.gnome.org/show_bug.cgi?id=664527

vbenes/gnome-boxes,vbenes/gnome-boxes