2006-04-08 jrandom

    * 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