* Disable the probabalistic drop by default (enable via the router config
property "tcp.dropProbabalistically=true")
* Disable the actual watchdog shutdown by default, but keep track of more
variables and log a lot more when it occurs (enable via the router
config property "watchdog.haltOnHang=true")
* Implement some tunnel participation smoothing by refusing requests
probabalistically as our participating tunnel count exceeds the previous
hour's, or when the 10 minute average tunnel test time exceeds the 60
minute average tunnel test time. The probabilities in both cases are
oldAverage / #current, so if you're suddenly flooded with 200 tunnels
and you had previously only participated in 50, you'll have a 25% chance
of accepting a subsequent request.