[Xmonad] darcs patch: Make a String description part of each Layout.

This change also adds a few layouts to the defaults, so that we'll be less likely to be unable to read the old state, if users remove a layout from their Config.hs. We really need some distinction between the defaultLayouts and the set of layouts that we know how to read. David Mon Sep 24 14:57:53 EDT 2007 David Roundy * Make a String description part of each Layout.