@Override
          public void receivedStatus(OperationStatus s) {
            rv.put(sa, s.getMessage());
          }
Get the versions of all of the connected memcacheds.

@return a Map of SocketAddress to String for connected servers
@throws IllegalStateException in the rare circumstance where queue is too
          full to accept any more requests
src/main/java/net/spy/memcached/MemcachedClient.java