libwacom: update from 0.7.1 to 0.15

pkgs/development/libraries/libwacom/default.nix

···
 { fetchurl, stdenv, glib, pkgconfig, udev }:
 
 stdenv.mkDerivation rec {
-  name = "libwacom-0.7.1";
+  name = "libwacom-0.15";
 
   src = fetchurl {
     url = "mirror://sourceforge/linuxwacom/libwacom/${name}.tar.bz2";
-    sha256 = "1agdaa1bv5mp4l32qgsw63swnnv0p279jiy9madgw4y3d8d12dwm";
+    sha256 = "04vppdj99cc0ya44n8p7zjk9yyw03v6fksw0a9n1gpnnsn4wardb";
   };
 
   buildInputs = [ glib pkgconfig udev ];