haskellPackages: New expressions for ipprint, Extra, bzlib, Unixutils

These are just the output of `cabal2nix` except that:

1. I had to change the auto-detected dependency in `haskellPackages.bzlib` from `bz2` (in [`bzlib.cabal`](http://hackage.haskell.org/package/bzlib-0.5.0.4/bzlib.cabal) since the name of the library is `libbz2.so`) to `bzip2` (the name of the Nix expression)
1. Similarly, I had to change the auto-detected dependency in `haskellPackages.Unixutils` from `crypt` (as specified in [`Unixutils.cabal`](http://hackage.haskell.org/package/Unixutils-1.52/Unixutils.cabal)) to `glibc`.  I'm not sure if this is the best way to do this — let me know if it's not.