[xmonad] Upgrading repo formats

[Adam Vogt]

Here are some graphs (plotted values) made from logs at
code.haskell.org.

http://code.haskell.org/~aavogt/darcsVersions/core.png
(http://code.haskell.org/~aavogt/darcsVersions/0)

http://code.haskell.org/~aavogt/darcsVersions/contrib.png
(http://code.haskell.org/~aavogt/darcsVersions/1)

It looks like darcs-1 is very infrequently used to access core or
contrib.

--
Adam