Improve logging of security related events
Security related actions and events should be logged into its own file / backend because
- they log data might be sensitive
- important information might drown in the amount of other messages
Additionally I'd like to see some hint if a user logged in or was re-authenticated due to an active token found in the session.
[+FEATURE] FLOW3 (Security): Security events are logged to own file and more verbosively
Aside from the FLOW3 system log - whose file name is now "System.log" -
FLOW3 now writes security related log messages into its own log file
Furthermore, the logging advices now report more detailed information
about re-authentication and authentication redirects.