Add a lint-nocolor Makefile target.

The lint-nocolor runs hlint without the --color flag; making it possible
to easily view the output in an emacs buffer (using M-x compile, for
instance)
Complete the LIR module.
Move the Lit data-type to HIR.hs.

Lit doesn't belong to Utils.Common -- LIR has its own low-level
representation of compile time-constants called 'Constant'.
Cabal integration.