Don't use deterministic nonces.
Clarify errors.
Tidy up.
Add experimental support for Remy.
Tidy up more.
Remove an unused import.
Add some acceptance tests.
Keep track of the listening port to be able to close it.
Refactor server connection establishment.

Instead of creating a new transport every time a Hello packet is received, wait
until an Initiate packet comes in. This means the server is more resistent to
attacks where an attacker sends Hello packets without intending to send
Initiate packets.

As a result, cookies are no longer random, but contain the server's generated
short-term key, encrypted.
Update Remy integration.