Added Prisms for Free.
Merge pull request #13 from supki/master

Added Prisms for Free.
Added recursion schemes to Control.Monad.Trans.Free
Church-encoded free monad transformer
Small change to foldFreeT
Export toFreeT and fromFreeT from Control.Monad.Trans.Free.Church
Added common instances for Control.Monad.Trans.Free.Church.FT
Merge branch 'freet-church' of github.com:roshanshariff/free into freet-church