Merge branch 'release/0.17'

api/funkwhale_api/music/management/commands/import_files.py

api/funkwhale_api/music/metadata.py

...i/music/migrations/0028_importjob_replace_if_duplicate.py

...funkwhale_api/music/migrations/0029_auto_20180807_1748.py

...funkwhale_api/music/migrations/0030_auto_20180825_1411.py

...funkwhale_api/music/migrations/0031_auto_20180914_2007.py

...nkwhale_api/music/migrations/0032_track_file_to_upload.py

api/funkwhale_api/music/models.py

api/funkwhale_api/music/permissions.py

api/funkwhale_api/music/serializers.py

api/funkwhale_api/music/signals.py

api/funkwhale_api/music/tasks.py

api/funkwhale_api/music/utils.py

api/funkwhale_api/music/views.py

api/funkwhale_api/musicbrainz/client.py

api/funkwhale_api/playlists/admin.py

api/funkwhale_api/playlists/filters.py

api/funkwhale_api/playlists/models.py

api/funkwhale_api/playlists/serializers.py

api/funkwhale_api/playlists/views.py