p2pool continues sending jobs to clients when internet is down
My ISP is pretty reliable, but I have noticed during occasional outages that my rigs keep running even when there's no way monerod or p2pool are connected to the internet. This is of course a waste of electricity as the rigs churn away at a job that is long out of date.

I know p2pool can detect when the network is down, because it won't be able to reach any peers on the sidechain. In such a condition, we should stop sending jobs to stratum clients to save energy until the net comes back up. This is sort of halfway done already, because if you start p2pool during an outage, it doesn't send any jobs until it establishes a connection to the sidechain. We just need to go back into that loop when the connection is lost later.