Cabal: Improve Haddock support

[Henning Thielemann]

On Sat, 8 Jul 2006, Isaac Jones wrote:

> Hi Henning.  I just applied & pushed your changes.  I had to resolve
> some conflicts, so I wonder if you can take a look and make sure it
> still works as you expect.  I tested it a bit and looks good.

I found no problems so far, too.

> I'm CCing the cabal-devel mailing list, are you on it?

Not yet. Is it high traffic?