[Xmonad] darcs patch: refactor layout interface.

Hi all, This is just my layout refactoring patch, re-recorded to deal with conflicts with the latest changes in XMonad. I've also written an example layout, which you can get with darcs get http://physics.oregonstate.edu/~roundyd/XMonad It's pretty useless... but shows a bit of how to use this layout scheme. David Thu Apr 19 08:30:07 PDT 2007 David Roundy * refactor layout interface. This change only changes functionality in that the tileFraction is now a per-layout variable. The main point is to add the flexibility to define layouts in the Config file.