more block types

[sid9102]

Filter blocks

1. Artist deduplicate
2. Artist filter
3. Deduplicate
4. audio features (https://developer.spotify.com/web-api/get-audio-features/)
5. Release date range

Source blocks

1. artist top tracks
2. my followed artists
3. my top tracks
4. Playlist miner (http://playlistminer.playlistmachinery.com/)

Combiner blocks

1. mixer (shuffle)
2. dj mixer (sort by tempo)