I reached a point where it works. Patches welcome - even without asking.
I should add a way to regenerate src.nix automatically too, but the information on what
to dowload is only inside their download script generated after configure.
There are more things that can be added: kde4 support, gstreamer, ...
I did not check that all the buildInputs are needed - most come from the old openoffice expression.
svn path=/nixpkgs/trunk/; revision=21969