Freesounds licensing

[JTN]

Something I've been wanting to pursue for a while is the possibility of getting the Freesounds soundset (that's currently downloadable by freeciv-modpack) into Freeciv proper.

This was originally compiled by Gavin van Lelyveld (MDCore on the old forum) from sounds at freesound.org. They used to license everything under CC Sampling+, which was fairly clearly awkward for us (e.g. DFSG-incompatible). More recently they've asked their users to move existing sounds to one of CC0, CC BY, or CC BY-NC. Not every user has done so, of course.

As a step towards this, I've worked through the original freesounds.AUTHORS file, updating the URLs and extracting the licence information, in case anyone wants to patch together a new soundset replacing the sounds with difficult licenses. The result is attached here.

(Assuming someone can work out which licenses are OK. CC0 is clearly GPL-compatible. I don't think CC BY-NC 3.0 can be OK, due to the non-commercial term. I don't know about CC BY 3.0; I don't know if anyone does.)

[cazfi]

Gavin commented on a related ticket on 20 Apr 2013, but nothing since: patch #3759