Now that we are targetting GTK+ 3.0, always build the full GTK+ stack,
along with librsvg and gtk-engines (so we have an SVG loader, and maybe
the user's GTK+ theme engine.)
New modules:
gtk+-3, gtk-engines-3, gnome-desktop-3, gdk-pixbuf, pixman, cairo, librsvg
Removed modules:
gir-repository
Add new requirements to gnome-shell-build-setup.sh and remove some
older requirements we no longer need.
Based on a patch from Colin Walters
https://bugzilla.gnome.org/show_bug.cgi?id=621845