Keeping the old solution for the ranges was too ineffective when it
came to enumerating all contained integers, the amount of elements was
too large to either expand the ranges into Sets or similar.
However, it turned out (after some thinking) to be fairly
straight-forward to check if consecutive ranges overlapped, and in
that case merge them. The solution therefore now parses the ranges,
sorts them on the first component and then merges them as far as
possible.
changes: JJ: M app/Day5.hs
Jacob Jonsson