QuickCheck instances.
The goal is to supply QuickCheck instances for types provided by the
Haskell Platform.
Since all of these instances are provided as orphans, I recommend that
you do not use this library within another library module, so that you
don't impose these instances on down-stream consumers of your code.
For information on writing a test-suite with Cabal see
http://www.haskell.org/cabal/users-guide/#test-suites
