Follow backwards incompatible API changes
While we are regularly bumping the fundamental dependency on glib-2.0 (currently >= 2.40) there is nothing done for e.g. gtk+-3.0.
Gtk.IconInfo has received an update which needed to be reverted to keep it working with gtk+-3.0 < 3.8.
Should we drop this change in favor of using the newly intended API? gtkiconinfo-3.8.diff