beets: Update to new upstream version 1.3.10.

We can now finally drop the mediafile and test fix patches, because they
were already coming from the upstream repository and are now included in
the release.

Also, this release brings two new plugins:

 * permissions: Fix permissions on music files as they are imported.
 * plexupdate: Notify a Plex server when the database changes.

The echonest_tempo plugin has finally been removed and so we can drop it
entirely. No plugin as of now tries to do interactive prompts on "beet
config" anymore, so we can test *all* plugins and without providing
dummy options.

The full list of changes can be found here:

https://github.com/sampsyo/beets/releases/tag/v1.3.10



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