Simplify firewall reconfiguration

[derekelkins]

If the UPnP public IP stuff is added, it may be worth adding support to attempt to open ports with UPnP. Alternatively, there are things like STUN. All of these solutions are unreliable and ugly and probably not worth the complexity of implementing.

Probably just some good direction (perhaps including the router address if UPnP doesn't fail completely), is the most appropriate thing here.