Setting a default port?

[lnicola]

bind_or can be used, but the default won't show up in the help message. I don't think there's anything that can be done to make it visible, but it's worth considering it.

There's also the issue of it failing due to e.g. permission errors. If I specify a port in the command line, I don't expect the default to be used if another program is listening on it.