Proposal: Add Functor instances for ArgOrder, OptDescr and ArgDescr

[Henning Thielemann]

On Mon, 19 Nov 2012, Erik Hesselink wrote:

> +1, I've defined these a couple of times as well.

http://www.haskell.org/pipermail/libraries/2011-November/017193.html

So, +1 from me.