beets: 1.3.19 -> 1.4.1

Full upstream release announcement:

https://github.com/beetbox/beets/releases/tag/v1.4.1

I had to rebase the keyfinder-default-bin.patch in order to apply with
the new release.

Other than that I didn't test whether beets works on my machine, as I
have a more or less temporary setup at the moment.

However, since the bump of mutagen to version 1.34 in commit
555928c2

, the mediafile tests fail and
thus this commit unbreaks beets.

Signed-off-by: aszlig <aszlig@redmoonstudios.org>