Consider --bind rather than --port/--address

[Nemo157]

I realise I'm going against a lot of prior server CLI design, but I much prefer a more descriptive command line argument than the normal --port argument. A design that I've used in the past is

BIND_ADDRESS=127.0.0.1:5476
--bind 127.0.0.1:5476

which can reuse SocketAddr::from_str for parsing.