Package versions match Debian jessie, except for a few differences
needed due to the different version of ghc pulling in a few buildin
packages with other versions.
Most of the patches were cherry-picked from past commits, since these are
older versions.
Added a cabal.config file; the result of running cabal freeze.
It's not used yet (needs a newer cabal than is in debian stable),
but the plan is that once the autbuilders are swiched to jessie,
this can be used to make cabal install the same versions of packages
that this patch got building, and so avoid breaking every time eg, yesod is
upgraded.
This commit was sponsored by Daniel Atlas.
