Clarify nomaclature of socket names in process_single and process_prefork

Clarify nomaclature of socket names in process_single and process_prefork

Fix talloc_steal in both cases to steal connected socket (from accept)
onto it's private structure, rather than stealing the bound socket.

Remove termination code from the prefork modal, we want the process to
still stay around, to serve future clients.

Andrew Bartlett and David Disseldorp