[Xmonad] darcs patch: Added LayoutMessages

[Andrea Rossato]

On Mon, Sep 24, 2007 at 06:19:06PM +0200, Andrea Rossato wrote:
> A layout must respond at least to 3 events:
>   1. a change in the stack -> UnDoLayout

UnDoLayout, which is actually useless, since we call doLayout within
Operations.windows, right?

>   2. a change in visibility:
>        A. workspace got hidden
>        B. LayoutSwitch -> the layout is not reachable anymore

Still, if we cannot use Hide for both, so we free the resources in
case of a layout switch. Right?
 
I'm a bit slow...

Andrea