The files given here only contain the ID3v2 tags, not the actual music.

- tests starting with numbers are taken from
<https://lists.id3.org/pipermail/id3v2/2005-September/000755.html>
- `liquidsoapNNNN.tag` tests refer to a particular [Liquidsoap
  issue](https://github.com/savonet/liquidsoap/issues)
