Merge pull request #24 from bfops/sss/open-union

open union: fixes #21
sss/hackage: remove -Werror

hackage doesn't like packages which break too easily =/
Merge pull request #25 from bfops/sss/hackage

sss/hackage: remove -Werror
master: version bump (for tag distinction)
Update README.md
sss/open-union: Data.OpenUnion1 -> Data.OpenUnion

Data.OpenUnion is now the public-facing interface for type-indexed
co-products.

TODO: incorporate ideas from alternative implementations such as
      <http://okmij.org/ftp/Haskell/extensible/TList.hs>
sss/open-union: don't export constructor for Union

resolves #13