GET /tracks/users/{userId} accepts repeated status values and returns the
albums each track belongs to. GET /tracks/users/{userId}/status-counts,
GET /albums/{id}/tracks/ids and DELETE /tracks with a list of track ids
are new.
GET /tracks/users/{userId} accepts repeated status values and returns the
albums each track belongs to. GET /tracks/users/{userId}/status-counts,
GET /albums/{id}/tracks/ids and DELETE /tracks with a list of track ids
are new.