FS-5453 --resolve this is a different issue, we just have to hangup the loopback channel so the loopback and the sip don't both execute the extension

ivrd doesn't use sigaction + SA_RESTART for SIGCHILD. An exiting
child process will interrupt accept() in the parent to handle
the signal, which makes accept() return -1 (errno = EINTR) after
the sighandler function returns.
Signed-off-by: Stefan Knoblich <stkn@openisdn.net>

Fixes repeatedly printing the 'Starting forking listener' message,
if stdout has been redirected into a logfile (for example).
Signed-off-by: Stefan Knoblich <stkn@openisdn.net>

FS-5402 --resolve the problem is ent originate has many channels and many causes to parse so we need to check it against all the causes

FS-5379: --resolve fix skinny phone codec agreement issues due to incorrect hardwired ptime, update field names for future coding to be more descriptive

Catch single channel RESTART/RESTART ACK events for non-B-channels,
that would lead to a NULL pointer dereference, because those do not have
per-channel private data (chan->call_data = chan_priv == NULL).
Signed-off-by: Stefan Knoblich <stkn@openisdn.net>