Patch kdiff3 so it will build with KDE 4.5.2

The DocBook DTD version must be at least 4.2 for validation.  Add a patch
to change version number in the DOCTYPE.

Submitted by Karn Kallio

svn path=/nixpkgs/trunk/; revision=24382

pkgs/tools/text/kdiff3/default.nix

@@ -10,6 +10,9 @@ stdenv.mkDerivation rec {
   # kdebase allows having a konqueror plugin built
   buildInputs = [ cmake qt4 perl kdelibs automoc4 phonon gettext kdebase ];
 
+  # Adjust the version of the DocBook XML to 4.2 ( so that it validates ).
+  patches = [ ./adjust-docbook-xml-version-to-4.2.patch ];
+
   meta = {
     homepage = http://kdiff3.sourceforge.net/;
     license = "GPLv2+";