add gtk-engines 2.20.2

pkgs/misc/themes/gtk2/gtk-engines/default.nix

···
+{ stdenv, fetchurl, pkgconfig, intltool, gtk2 }:
+
+stdenv.mkDerivation {
+  name = "gtk-engines-2.20.2";
+
+  src = fetchurl {
+    url = "ftp://ftp.gnome.org/pub/gnome/sources/gtk-engines/2.20/gtk-engines-2.20.2.tar.bz2";
+    sha256 = "1db65pb0j0mijmswrvpgkdabilqd23x22d95hp5kwxvcramq1dhm";
+  };
+
+  buildInputs = [ pkgconfig intltool gtk2 ];
+
+  meta = {
+    description = "Theme engines for GTK+ 2";
+    license = stdenv.lib.licenses.lgpl21Plus;
+    platforms = stdenv.lib.platforms.linux;
+  };
+}

pkgs/top-level/all-packages.nix

···
 
   oxygen_gtk = callPackage ../misc/themes/gtk2/oxygen-gtk { };
 
+  gtk_engines = callPackage ../misc/themes/gtk2/gtk-engines { };
+
   gnome_themes_standard = callPackage ../misc/themes/gnome-themes-standard { };
 
   xfce = xfce4_10;