Support recognition inhibit

[denis-stepanov]

It would be interesting to have a command line option which would start AdVent in inhibited mode, i.e. not running any recognition (or running but not taking any action). This would allow using AdVent in fully manual mode as TV remote. Note that it is different from --tv_control nil which would disable any actions, including manual. An equivalent command to inhibit / activate recognition would be also needed.

[denis-stepanov]

An equivalent effect for now could be reached with options like -n 1 -i 1 -c 100, i.e., forcing a situation where a hit would be highly unlikely whatever the input is.