uds: don't output "Connection refused"

When phc2sys is started before ptp4l or it is interrupted before ptp4l has
a chance to reply to its query, the "uds: sendto failed: Connection refused"
message is output. This is not an interesting message.

Also, don't output the "failed to send message" error from pmc_send, as
all transports output errors in their send routine.

Signed-off-by: Jiri Benc <jbenc@redhat.com>
Respond with an error to management messages to non-existing ports

Signed-off-by: Jiri Benc <jbenc@redhat.com>
Remove unneeded parameter in port_forward

This parameter was made obsolete by the common address refactoring.

Signed-off-by: Jiri Benc <jbenc@redhat.com>
Implement port_forward_to

Signed-off-by: Jiri Benc <jbenc@redhat.com>