Documented Template Haskell module for Free monad.
Added support for InfixC to Control.Monad.Free.TH. Extended docs.

The example can now be run by itself and interacted with. It also makes use
of the newly-added InfixC support.
Clarified behaviour of record types and notation in Control.Monad.Free.TH.
Merge pull request #44 from team-free/haddock

Documented Template Haskell module for Free monad.