[Xmonad] darcs patch: use a global IORef to keep list of urgent windows

[Don Stewart]

me:
> On Sat, Oct 27, 2007 at 02:52:28AM -0400, Devin Mullins wrote:
> > Somebody asked for the ability to display which workspaces had urgent windows in them in the logHook.
> > Well, here it is. (Well, the core state-tracking functionality.) Please provide input on:
> 
> >  - If it's bug-free (no space-leaks, safe-ish unsafePerformIO, etc.)
> Clarification: Those bugs I mentioned in the last email applied before this patch, too.
> 
> >  - If it's useful (whoever you were that asked for it)
> shachaf says he can make it work. He should submit a logHook helper
> (perhaps in UrgencyHook, because of the extra dependency on
> Config.urgencyHook) when he's done. :)
> 
> Any other reason this isn't applied?

You expressed hesitation? :)

-- Don