Feature request: watched IP address update logic

[tripleee]

sevenmentor.com in particular is notoriously switching IP addresses like others change underwear. It would be nice if Halflife could periodically check their IP address, and perhaps even automatically add the new address to the IP watchlist when it changes.

(My practice has been to keep the old addresses on the watch list still. If we find that this is problematic, maybe also eventually figure out a way to remove old ones.)