Added FixTerm to the calculus and inferencer.
Added support for recursion between groups of let's.
Merge branch 'master' of https://github.com/AardvarkSoup/HaskellControlFlow
Fixed merge error.
Recursion works! At least, as far as the simple cases I tested go.

Note that the fixpoint definitions of recursive functions look pretty horrific
when formatted.
Merge branch 'master' of https://github.com/AardvarkSoup/HaskellControlFlow
Merged stuff.