unintended breakage

[Matthias Clasen <matthias clasen gmail com>]

The GTK+ 2.91.7 release includes a change causing breakage that I
hadn't anticipated:

gdkconfig.h is no longer a standalone header that can be directly
included. Instead, just include <gdk/gdk.h> (or, in fact, nothing at
all since GTK+ includes already bring that in). This affects all
modules using a copy of EggSmClient (gnome-session, vino, seahorse,
gnome-utils, evolution, gnome-terminal, brasero, gedit, file-roller,
evince, gnome-panel, epiphany, totem, gnome-games and nautilus).

A few modules fail to build with other GTK+ related issues. I'll be
working on patches for those today.