* Invalidate the current session when the user logs out
* Special variables defaultemail and show_admin are now included automatically in all template variable spaces. Scripts no longer need to manually fetch these and send them for the sidebar to work properly.
* The login page now displays a special message when an admin login is required to continue.
git-svn-id: svn://10.0.0.236/trunk@199800 18797224-902f-48f8-a5cc-f745e15eee43
