Couple of web flow thoughts

[Cantor, Scott]

Starting to put together a sample flow for the command line tool, and I
noted that the current "start" action is one that assumes an HTTP servlet
request/response pair. We probably want to isolate that to its own action.

The other thought I had was that I'm not sure if I buy putting these
concrete Action classes into an -impl package. It seems to me that if
they're intended to be usable by deployers in their own custom flows, and
they have input/output contracts, that makes them APIs.

Or maybe they're something that isn't quite either. But they're not just
implementation details if we can't change them at will.

-- Scott