[xmonad] darcs patch: Applicative instance for X; new startupHook

[Don Stewart]

byorgey:
>    Hi all,
> 
>    Here are two patches to the core, one to add an Applicative instance for
>    X, and another which adds a startupHook :: X () to the config.  I wrote
>    them to support updates to PerWorkspace (patch to follow shortly), but I
>    think they're both useful in and of themselves, especially the
>    startupHook. 
> 
>    Mon Feb  4 14:24:45 EST 2008  Brent Yorgey <[1]byorgey at gmail.com>
>      * Add a startupHook.
>      The only thing I am not sure about here is at what exact point the
>      startupHook should get run.  I picked a place that seems to make sense:
>      as late as possible, right before entering the main loop.  That way all
>      the layouts/workspaces/other state are set up and the startupHook can
>      manipulate them.
> 
>    Mon Feb  4 14:23:48 EST 2008  Brent Yorgey <[2]byorgey at gmail.com>
>      * Core.hs: add an Applicative instance for X

I've applied this.

-- Don