Listen to a control socket on an IPv4 as well through an IPv4-mapped IPv6 address.
Listen to a control socket on an IPv4 as well through
an IPv4-mapped IPv6 address.

Reported by:	Julian H. Stacey <jhs__at__flat.berklix.net>
Test by:	Julian H. Stacey <jhs__at__flat.berklix.net>
MFC after:	1 week

jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase