r3026: - added automatic retry to messages when the servers listen queue is
full. This means callers can just "send and forget" rather than
having to check for a temporary failure. The mechanism takes nice
advantage of the timed events handling is our events code. A message
will only fail now if we completely run out of some resource (such
as memory).
- changed the test code not to do retries itself, but only to warn on real failures
(This used to be commit
8cddc610a25e64c1ad39dd6a2fc2e7f467e04fc9)