darcs patch: [PROOF OF CONCEPT] build readline package with libedit

[Christian Maeder]

Robert Dockins wrote:
> 
> http://hackage.haskell.org/cgi-bin/hackage-scripts/package/Shellac-compatline-0.9

Brilliant, it works as expected. Thanks again.

>> How do you set up the cabal file for such a package?
> 
> Cabal configuration flags can do this sort of thing.

Yes, good to see this.

>> The license entry could simply mention the possible readline dependency.

We'll see if the license will be a problem.

Cheers Christian