* Add ability to configure “own” addresses
This configuration option permits the declaration of external or public
addresses instead of attempting to learn them from port forwarding or
interfaces. This is useful in situations where it isn’t possible to
accurately obtain the correct external addresses that peers should use.
* Update args and use better parse listen address
Add the --advertise_addresses control argument to accompany the new
configuration option. Also parse the listen address/port to extract the
port to advertise with advertise_addresses instead of assuming it is
just a port.