* Do not have linktest daemon connect to boss; have it connect to
  local node elvind like all other local agents. Remove the event
  generation code (linktest was sending a KILL event to all other
  linktest programs), and replace with a system() call to tevc, which
  sends the event through the scheduler and exits; this will avoid a
  zillion tcp connctions to boss from the linktest daemon.

* A couple of process group changes to linktest daemon; the daemon
  appeared to be killing itself off.

* Fix to run_linktest.pl; It was just hanging after it completed,
  cause its child ltevent process was still running. Changed to record
  child pid, and kill/close ltevent child before exiting.