[xmonad] darcs patch: Add Font layer supporting an Xft backend... (and 3 more)

More work on Xft, this isn't ready for mass consumption yet. Notably, XMonad.Prompt and friends don't build with this patch. Fri Nov 16 06:06:53 CST 2007 Clemens Fruhwirth <clemens@endorphin.org> * Add Font layer supporting an Xft backend. Make Tabbed.hs a user of this layer. Fri Nov 16 06:25:51 CST 2007 Spencer Janssen <sjanssen@cse.unl.edu> * Font.hs: tabs Fri Nov 16 06:35:52 CST 2007 Spencer Janssen <sjanssen@cse.unl.edu> * Font.hs: CPP around Xft calls, use a data type rather than Either Fri Nov 16 06:42:11 CST 2007 Spencer Janssen <sjanssen@cse.unl.edu> * Use Xft automatically if available