unwrapPipe now works as one might expect.
Moved the last/first distinction up slightly under the pipe typechecking.
The original did not make sense.
Implemented the same for Farm as Pipe.
Single ord typechecking added.
Single Map, Cluster, Reduce, and Feedback added.
Top-level workflows of multiple length are now checkable.
Tidied typechecking, kind of skeleton no longer needed or observed.