Create a basic monitoring infrastructure for large scale events

At present we don't seem to have alarming infrastructure or anything else that would notify us of events (even noisy attack attempts) within the network. Bandwidth authorities are generating the heuristics congestion attacks need to modify to effect client behavior, so we should be able to trivially detect large deltas (for instance, if half the network suddenly seems to vanish) and get a notification.

I don't believe that we should invest too much effort here since this probably isn't an arms race we'd do very well in. However, we shouldn't rely on users to notify us of DoS attempts or other particularly noisy attacks.

Putting this under metrics to get Karsten's thoughts. Maybe this is somehow already being monitored? If not then general purpose alarming (which could also replace my consensus tracker script) might be a fun project to hack on later, and possibly be a good candidate for GSoC next year. :)

Cheers! -Damian