and restarts PHP SESSION

Also include
  * username validation -- no spaces or weird chars
  * no longer base64 encoded sha1-hex hash for CSRF token
  * refresh login page every two hours to keep session active

Protect againts cross-site request forgery attacks by requiring a special
form-field or header to be sent with requests that modify ticket system
data.

This meant a slight change to the AJAX ticket locking mechanism. It was
defined to lock with a GET request; however, GET requests are defined as
safe methods and should not modify backend data (such as a lock
acquisition). Therefore, the the lock acquire AJAX method was changed to
require a POST method.

Also remove old, no-longer-used staff panel include files