[Xmonad] darcs patch: first shot at a floating layer

[David Roundy]

Another couple of ideas for the float layer:

mod1-button2 should raise a window that's not at the top, but lower to the
very bottom one that's already on top.  Otherwise it can be hard to find
obscured windows.  But once this behavior is configurable, of course, this
change will be less critical.

When dragging a window, I'd rather it was displayed is it'll be when I
release it.  Currently the window is raised to the top while being dragged,
but then released at the current stacking level, with the result that you
can easily "lose" the window you're dragging, if you drop it under a larger
window.  This change wouldn't prevent that loss, but would make it obvious,
since the window would be hidden when you drag it under the larger one.
Another solution would be to always raise windows when moving them.
-- 
David Roundy
Department of Physics
Oregon State University