Performs the ASP.NET application logout.
true, if the log off can be canceled in the XafApplication.LoggingOff event handler; otherwise - false;
Triggers the XafApplication.LoggingOff and XafApplication.LoggedOff events. You can handle the former to cancel the log off process, and the latter, to be notified when a user has logged off. Note that if the canCancel parameter is false, the Cancel parameter of the LoggingOff event handler is ignored.