* Process inbound tunnel requests more efficiently
* Proactively drop inbound tunnel requests if the queue before we'd
process it in is too long (dynamically adjusted by cpu load)
* Adjust the tunnel rejection throttle to reject requeusts when we have to
proactively drop too many requests.
* Display the number of pending inbound tunnel join requests on the router
console (as the "handle backlog")
* Include a few more stats in the default set of graphs