Networking: A placeholder for some missing logic in the previous change...

Networking:  A placeholder for some missing logic in the previous change related to monitoring network status for dup'ed sockets.  If one of the dup'ed socket's is closed, then network monitor resources associated with that one socket must be recovered.  Also, in the event that socket is being used on one thread, but then closed on another, any threads waiting for events from the socket should be informed of the closure.  That latter requirement is not implemented because current data structures do not support it.