So we can use them in binary cache files.

Also relax version constraints on binary to work with binary-0.5.*,
which requires that we expose Distribution.Compat.Binary from Cabal.

D.Compat.Binary provides the Gerics support that we need to be able to
derive instances when using binary-0.5. It's useful to be able to use
binary-0.5 since that's the version bundled with older ghc versions.