#19 Add support for darcs

[Anonymous]

It would be very nice if tkdiff would
support the version control system darcs
(http://abridgegame.org/darcs/) in a way similar to
its support for cvs (and some other version control
systems). One feature of tkdiff that I use very often
is to just do 'tkdiff <filename>' in a
checked-out cvs source tree to see what changes I
have made vs. the repository.

benjamin.franksen@bessy.de