Adding pygobject3 (for bluez4).

bluez-simple-agent fails to work otherwise.
We discussed this a bit on #486, and this looks like the simplest way to
get bluez-simple-agent again.

pkgs/development/python-modules/pygobject/3.nix

@@ -0,0 +1,19 @@
+{ stdenv, fetchurl, python, pkgconfig, glib, gobjectIntrospection, pycairo, cairo }:
+ 
+stdenv.mkDerivation rec {
+  name = "pygobject-3.0.4";
+   
+  src = fetchurl {
+    url = "http://ftp.gnome.org/pub/GNOME/sources/pygobject/3.0/${name}.tar.xz";
+    sha256 = "f457b1d7f6b8bfa727593c3696d2b405da66b4a8d34cd7d3362ebda1221f0661";
+  };
+
+  configureFlags = "--disable-introspection";
+
+  buildInputs = [ python pkgconfig glib gobjectIntrospection pycairo cairo ];
+
+  meta = {
+    homepage = http://live.gnome.org/PyGObject;
+    description = "Python bindings for Glib";
+  };
+}