Removed old attempt at problem 12.
Moving problems to shorter names.
Problem 128: operational, but not fast enough.
Haskell problem 2 complete, but very inelegant.
Haskell p2: use let binding to be more efficient
Tidying haskell p2
First attempt at Haskell problem 3.
Correct version of Haskell p3.
Haskell problem 4: first pass, correct.