See #261: Added a rate-limiting (throttling system) to limit the number of requests handled per user/IP

Added "refresh=true" API param to artist, track and album detail to retrieve up-to-date data if needed

Increase the security of JWT token generation by using DJANGO_SECRET_KEY as well as user-specific salt for the signature

Fix #867: Added a SUBSONIC_DEFAULT_TRANSCODING_FORMAT env var to support clients that don't provide the format parameter

This reverts commit 68b21d70.

This reverts commit 8b47af8b, reversing
changes made to c0055b3b.