* Adjust how we pick high capacity peers to allow the inclusion of fast
peers (the previous filter assumed an old usage pattern)
* New set of stats to help track per-packet-type bandwidth usage better
* Cut out the proactive tail drop from the SSU transport, for now
* Reduce the frequency of tunnel build attempts while we're saturated
* Don't drop tunnel requests as easily - prefer to explicitly reject them
* Include a combined send/receive graph (good idea cervantes!)
* Proactively drop inbound tunnel requests probabalistically as the
estimated queue time approaches our limit, rather than letting them all
through up to that limit.
