Haskell bob test improvements

Implement #614 for Haskell, and also add a test for multiple kinds of whitespace instead of just `' '` to encourage using `Data.Char.isSpace` over `(== ' ')`

The example code passes all tests, after a quick fix for a failure introduced by the new test in 2476edf

@etrepum should probably look over this since the Haskell stuff is mostly his.