9.25: protocols can now be tied to ports; i.e. jelpport = or ts6port = in configuration.
            added connection methods ->possible_protocols() and ->possibly_protocol().
            ->register_registration_command() now takes an optional 'proto' option.
            registration commands can now be registered automatically from %registration_commands.
            JELP registration commands moved from Core::RegistrationCommands to new module JELP::Registration.
            listen on *port.