The reasoning is that this string is only ever likely to refer to the
version of the primary/initial client (the CLI application, written in
Python, that you get with "pip install magic-wormhole"). When there are
other implementations, with unrelated versions, they should obviously
not pay attention to a warning about the other implementation being out
of date.
* add "released" ack-response for "release" command, to sync w.close()
* move websocket URL to root
* relayurl= should now be a "ws://" URL
* many tests pass (except for test_twisted, which will be removed, and
test_scripts)
* still moving integration tests from test_twisted to
test_wormhole.Wormholes
