Clarify nature of ACDB data files (wrt. DFSG)

[slyon]

Those .acdb and .qwsp files seem to be binary blobs. We should clarify their source wrt. DFSG.

Requested via: AudioReach/audioreach-conf#90

[slyon]

As per AudioReach/audioreach-conf#90 (comment)

The calibration data in the .acdb files is created using the ARC (AudioReach Composer) tool the open-source successor to QACT. The tool provides a GUI where you configure audio topology, routing, and tuning parameters for a specific hardware platform (codec, amplifier, microphone layout, etc.), and then exports the binary .acdb calibration database and the .qwsp workspace file.

So the .qwsp file is effectively the "source" it is the ARC workspace that was used to generate the corresponding .acdb. Both are checked in together so that the calibration can be reproduced or modified by opening the .qwsp in ARC.

This should clear the binaries wrt. DFSG. Maybe we need to re-build the .acdb files during build from its corresponding .qwsp, which might be a bit card, due to ARC being a Windows application.

[slyon]

Moving into Section: non-free/sound, until we can re-create the .acdb binary calibration-data from the .qwsp sources at build-time.