Revert Merge x-updates into master due to mesa bloat

See #490 discussion.

This reverts commit 1278859d31, reversing
changes made to 0c020c98f9.

Conflicts:
	pkgs/desktops/xfce/core/xfce4-session.nix (take master)
	pkgs/lib/misc.nix (auto)

pkgs/development/libraries/gdk-pixbuf/default.nix

@@ -1,31 +0,0 @@
-{ stdenv, fetchurl, pkgconfig, glib, libtiff, libjpeg, libpng, libX11, xz
-, jasper }:
-
-stdenv.mkDerivation rec {
-  name = "gdk-pixbuf-2.28.1";
-
-  src = fetchurl {
-    url = "mirror://gnome/sources/gdk-pixbuf/2.28/${name}.tar.xz";
-    sha256 = "1fy2a05xhfg7gy4l4aajsbmgj62zxhikdxqh6bicihxmzm1vg85y";
-  };
-
-  # !!! We might want to factor out the gdk-pixbuf-xlib subpackage.
-  buildInputs = [ libX11 ];
-
-  nativeBuildInputs = [ pkgconfig ];
-
-  propagatedBuildInputs = [ glib libtiff libjpeg libpng jasper ];
-
-  configureFlags = "--with-libjasper --with-x11";
-
-  postInstall = "rm -rf $out/share/gtk-doc";
-
-  meta = {
-    description = "A library for image loading and manipulation";
-
-    homepage = http://library.gnome.org/devel/gdk-pixbuf/;
-
-    maintainers = [ stdenv.lib.maintainers.eelco ];
-    platforms = stdenv.lib.platforms.linux;
-  };
-}