* feature: AD support nested groups (resubmit #7175)
Don't let groups with periods in the name cause issues.
* Merge #7245 into this PR
* Capture Exceptions in get_userlevel()
* Throw generic error if auth_ad_debug is not enabled to prevent information leak.
* fix: minimize session open time
page/graphs speedup part 2
Write close the session as soon as we no longer need to write to it. Prevents the session from blocking other requests.
Do not run through full authentication functions if the session is already authenticated.
Removes password from the session as well as some items to prevent session fixation from #4608.
WARNING: This will cause issues for ad/ldap users who do not have a bind user configured!
* Do no erase username when using cookie auth.
Properly close the session in ajax_setresolution.php
* write close the session as soon as possible in ajax_setresolution.php
* Remove session regeneration. It is not compatible with the current code and would require more changes.
* Totally refactor authentication. Extract code to functions for re-use and improved readability
* Use exceptions for authentication and error logging
Tested: mysql, ad_auth with and without bind user
* fix a couple scrutinizer issues
* fix reauthenticate in radius
