__WikiSecurityEvent__ is a sublass of WikiEvent for security events: login/logout, wiki group adds/changes, 
and authorization decisions. When a WikiSecurityEvent is constructed, the security logger is notified. It defines the event types as described below. 

These events are logged with priority {{ERROR}}:

* __login failed - bad credential or password__ : When a login fails due to wrong username or password.

These events are logged with priority {{WARN}}:

* __login failed - credential expired__ : When a login fails due to credential expiration.
* __login failed - account expired__ : When a login fails due to account expiration.

These events are logged with priority {{INFO}}:

* __login authenticated__ : When a user authenticates with a username and password, or via container auth.
* __logout__ : When a user logs out.
* __session expired__ : When a session expires.
* __user profile name changed__ : When a user profile name changes.

These events are not logged:

* __access allowed__ : When access to a resource is allowed.
* __access denied__ : When access to a resource is allowed.
* __login initiated__ : When a user's attempts to log in as guest, via cookies, using a password or otherwise.
* __login anonymous__ : When a user first accesses JSPWiki, but before logging in or setting a cookie.
* __login asserted__ : When a user sets a cookie to assert their identity.
* __user profile saved__ : When a user profile is saved.
* __add group__ : When a new wiki group is added.
* __remove group__ : When a wiki group is deleted.
* __clear all groups__ : When all wiki groups are removed from ~GroupDatabase.

These events no longer exist:

* __add group member__ : DESCRIPTION TBD
* __remove group member__ : DESCRIPTION TBD
* __clear all members from group__ : DESCRIPTION TBD