WCCP: Fix memory leak in mask assignment, improve debuggsing.

WCCP: Fix memory leak in mask assignment, improve debuggsing.

* Release temporary weight array allocated on each HERE_I_AM packet sent
  by Squid. For mask assignment these were not released properly and may
  build up to a significant size of memory over time.

* Add debug traces to send() events to report failures sending packets

* Also, on HERE_I_AM event send() failure, reduce the timeout to 2sec
  for the retry in a crude attempt to prevent router state flapping.

* Silence compiler warnings on use of connect() to disconnect a socket.
  Inconsistent OS behaviour makes the result useless in this case.

 Detected by Coverity Scan. Issues 740329, 740330, 740331, 740332,
    740333, 740441.