Make WebKit use libsoup 2.31.2 via deepOverride. Edit a few packages that were overridable but did not allow extra arguments. Remove a catch with deepOverride that pkgs.lib had this attribute in a different sense.

svn path=/nixpkgs/trunk/; revision=22529

pkgs/development/libraries/consolekit/default.nix

@@ -1,5 +1,6 @@
 { stdenv, fetchurl, pkgconfig, dbus_glib, zlib, pam, glib, 
-  libX11, polkit, expat }:
+  libX11, polkit, expat
+  , ...}:
 
 stdenv.mkDerivation rec {
   name = "consolekit-0.4.1";