* Add a packet capture mode (-c) option so that pcapper can be used
  the same way that tcpdump is used, to write captured packets to an
  output file. When using capture mode, stats are not collected or spit
  out. I need to think about how feasible it is to do both at once; it
  started to look like a mess.

  I added a snaplen (-l) option to be used with capture mode, to
  specify the snaplen that is passed to the pcap library.

* Beef up the event interface, adding a TRACEINFO event type, so that
  you can send START, STOP, KILL events to the pcapper. So, you can
  start and stop packet capture for a link/lan, or for a single node
  on a link/lan (much the same way as you acn control the delay
  agent).