Decoratione: generate rectangles first, and create windows accordingly
Decoratione: generate rectangles first, and create windows accordingly

With this patch Decoration will first generate a rectangle and only if
there is a rectangle available a window will be created.

This makes the Decoration state a bit more difficult to process, but
should reduce resource consumption.

darcs-hash:20080219122115-32816-56ccaf1fed88e2830d6cd76d346eaca119d3143a

kmels/xmonad-launcher,kmels/xmonad-launcher