Merge branch 'master' of https://github.com/NixOS/nixpkgs into update

Conflicts:
	pkgs/development/libraries/haskell/text-binary/default.nix
	pkgs/top-level/haskell-defaults.nix
	pkgs/top-level/haskell-packages.nix
Use lens-4.6.0.1 instead of lens-4.4

lens-4.4 doesn't build because it requires an old version of text.
Merge pull request #5 from basvandijk/update

Merge upstream master
Merge remote-tracking branch 'refs/remotes/ghcjs/master'

Conflicts:
	pkgs/development/libraries/haskell/text-binary/default.nix
	pkgs/top-level/haskell-defaults.nix
	pkgs/top-level/haskell-packages.nix