[Xmonad] darcs patch: make borderWidth dynamically configurable.

[Donald Bruce Stewart]

droundy:
> This is a sort of hypothetical change.  I like this design more than the
> recursive import approach.  I'm not sure how often people will want to
> dynamically adjust the width of their borders, but I also don't see any
> reason to forbid it.

Hmm, interesting. Not massively compelling yet, but something to keep in
mind.

-- Don