* Address static sockaddr buffer in server_body (Mostly by saying
   "YOU worry about it!" heh heh. boost signals appear to happen in
   the thread they originate from, so both the signal for the thread
   you should monitor and the copy of the incoming address should
   happen as if they're in a critical section, even though I'm not locking
   anything.

 * Added new service class interface you can optionally derive from
   which will copy the originating address for you when it's created
   or copied.

 * Updated echo service to use new service class interface.

 * Updated test_client_server to catch the new service class thread
   signal from the server and join and delete the service class thread
   before joining the server and exiting.