hackage-packages.nix: update Haskell package set

This update was generated by hackage2nix v20150922-45-g1161457 using the following inputs:

  - Nixpkgs: https://github.com/NixOS/nixpkgs/commit/8a5e5c46a19625d8f0149c9d3fec3ecc298baa1c
  - Hackage: https://github.com/commercialhaskell/all-cabal-hashes/commit/c8d16c7fd21071de12e15ba2c05a4f7b4bc97594
  - LTS Haskell: https://github.com/fpco/lts-haskell/commit/89c3b45370ec1742d9e029ff4e5271316031b84b
  - Stackage Nightly: https://github.com/fpco/stackage-nightly/commit/98e337bf6bf8efb772babe252e3f0027d8b6f859