mpegts: fix some issues with network scanning

mux matching was far too strict and resulted in a failure to update muxes
with new modulations etc... Also frequency changes were not detected, so
there is some attempt to handle greater changes (mostly just DVB-S, could
be extended).

And where ONID/TSID are set, they are compared as an additional check.
I think it's a case of suck it and see, but on my Astra 28.2E scan this
did a nice job of cleaning up (including tying together modded) muxes.
tsdemux: do not show continuity error in first seconds of streaming

Most hardware stabilizes things after tuning and these messages are
irritating.
capmt: minor fixes (cleanup on socket close)
descrambler: another key-timing fix
mpegts_network_dvb: fix the comment
descrambler: unify log messages, some minor logic changes
cwc: return back the key composition - seems like some CA cards returns only single key
Revert "cwc: return back the key composition - seems like some CA cards returns only single key"

This reverts commit da05976c3209df9ef448cb672ee1dbbf4a4d813e.
descrambler: allow single key updates again
capmt: allow single key updates again
descrambler: check for key validity
capmt: there are multiple waiters - use pthread_cond_broadcast()
mpegts_mux_dvb: fix the dvb-s position parsing
scanfile: fix parsing for the latest formats
mpegts_network_dvb: fix the orbital position check for predefined muxes (scanfile)
dvb_support: add dvb_mux_conf_str()
dvb autodiscovery: more logs and improvements

- added logs for the scanfile mux creation
- added logs for the autodiscovery mux creation
- added logs for the autodiscovery mux changes
- use also symbol rate for the equal mux comparison
- handle the delivery system change (dvb-s / dvb-s2 switch for example)
descrambler: tiny log message updates
capmt: fix the pid open/close handling
capmt: another pid fix for the stop filter routine