Gearing up for 1.20

[Johan Tibell]

Hi,

I'd like to get 1.20 out by the end of the month. There's enough
interesting stuff in there to be worth making a release.

Here are the current open issues for the 1.20 milestone:
https://github.com/haskell/cabal/issues?milestone=21

These are mostly feature requests so we could technically do without
any of them, but it would be nice to knock some off if people have
some free weekend hacking time.

Thoughts?

-- Johan