Permanently sort a Spotify playlist by some field.
Spotify's mobile app currently does not allow playlist sorting, only using the default ordering, making it difficult to locate a specific track.
Place files into a directory within ~/spotify, and then search for
spotify:app:sorterizer in Spotify.
Note that this is an unofficial Spotify app and not available in their app
store. When adding to favorites, it will only remain for the current session of
the Spotify application, and must be re-added via spotify:app:sorterizer upon
restart. This and the directory limitation are imposed on all unofficial apps.