Super User token is very secret. The Tracking API should allow for more flexibility and allow any "admin" token for the site being tracked.
For performance, we don't want to query the DB on each Tracking API request. So we can cache in the Tracker cache files the list of all allowed admin token_auth and check against this list.
(In ) Fixes #2302 Now, setTokenAuth on the Tracking API can accept the Super User token_auth or any 'admin' user token_auth (the token are cached in the tracker cache file, which is now flushed when users or permissions are changed)