Request handling is sped up by processing API config once, at application start, rather than on every request. Additionally, we now avoid an unnecessary Python->JSON->Python roundtrip.
Dead code from the JSON-RPC support has been removed.
The api_backend and api_backend_service modules have been removed; nearly all of that code was dead anyway.
The OAuth scope support now properly supports situations where multiple scopes must be present for a request to proceed.
Added a deprecation warning when auth_level is used.
Rationale: Breaking changes in scope handling