Bug reported by: https://github.com/jfpanisset

fit in a 8KB buffer, since parsing expects a complete response
from the router, increase the maximum buffer / response size
to handle 3,200+ line response.

Signed-off-by: Jean-Francois Panisset <panisset@gmail.com>

  --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

This makes the program compatible with future protocol updates.
Before it was just dying so even if the new protocol was compatible
the program needed to be recompiled.

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).

--list-proc-units was documented in 1.0 release but it was never
wired up to work. --list-frames was not documented in 1.0 and it
wasn't working either.

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.

Previously it seems to have worked by accident (there was not enough
space for the end NULL byte).

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

After sending command to videohub the response must read before
another commands is sent.

This prints the device configuration as videohubctrl parameters thus
allowing the configuration to be restored later.

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

Show port numbers next to inputs and outputs and locks next to
outputs to better reflect the logic for their manipulation.

Now the short parameter is the first letter of the long parameter
which is much more natural.