Multiple fixes/updates

Sorry these are all in one pull request, but.. It's a lot easier to deal with that way.

These changes do the following:
- Update to version 4.0 of edwardk's libraries as dependencies, including swapping comonad-transformers for comonads
- Fix issue #2, the cyclic dependency between interpret, liftProgram, and fromProgram which caused all three to hang
- Fix a typo in the documentation that I noticed while I was in there
- Bump the version to 0.6.0.0