Handle errors in generic camd code instead of protocol code.

This makes do_emm() and do_ecm() take the same parameters. The next
step is to make them take struct camd_msg as single parameter.

This move is in preparation to use struct camd_msg in camd ops.

When the input is MPTS and output filtering is enabled, rewrite output
PAT to include only the single program that is decoded.

I should remember to add options in README.

PATH_MAX is not in c99 and also struct ip_mreq. With -std=c99
tsdecrypt do not compile with gcc 4.5.

This workaround is no longer needed because camd socket is now set
TCP_NODELAY and this fixes OSCAM communication.

This way it works better when many packets are sended. Without
NODELAY, OSCAM sometimes gets packets boundaries wrong especially
when there are lots of packets (test with emm stream of 16000+
packets per minute).

Without this the STOP event was lost most of the times because
tsdecrypt exited before the thread delivered the event.

This prevents unnececary warnings. Sometimes OSCAM responds with error
and on the next query everything is OK. So before raising errors flags
try a couple of times.