Logout the current user Add code to the logout button to remove the current user from the session and to redirect the browser window to the login page. Part of flys/issue916 (Logout: "Abmelden" Knopf mit Funktion belegen)

<?xml version="1.0" encoding="UTF-8" ?>
<rest-server>
    <!--  The port which the ArtifactDatabase (ArtifactServer) will bind to. -->
    <port>8999</port>
    <listen>localhost</listen>
</rest-server>