Thanks to alex # dyaconov.com for the test data

It doesn't seem to do anything and just spams that logs. Thanks to
Jean-Francois Panisset for the report.

I have no idea what it does unfortunately.

Thanks to Yannick BARBEAUX for the report.

  --list-vinputs   ->  --list-inputs
  --list-voutputs  ->  --list-outputs
  --list-moutputs  ->  --list-monitor
  --vi-X           ->  --in-X
  --vo-X           ->  --out-X
  --mo-X           ->  --mon-X
  --se-X           ->  --ser-X

My Videohub Micro doesn't support this extra but I suppose the
bigger models do (at least the official software v6 reads this
value and shows it instead of the device model).

It is not tested on a real hardware. The number of frame buffers
is assumed to be the same as number of serial ports (as good guess
as any).

It is not tested on a real hardware.

This allows adding of new commands without any changes to command
parsing and generation code.

Some very old and broken compilers complain about shadowing bcopy().

Add support for setting video input/output names, video output locking
and video output routing.

It is not a good idea parse_cmd() to just die().