Implement UserService method to remove current user from session For being able to logout a user UserService must provide a method the remove the current user object from the session. Part of flys/issue916 (Logout: "Abmelden" Knopf mit Funktion belegen)

<config>
    <server>http://localhost:8181</server>

    <projectlist>
        <!-- The interval to update the user's projects (in ms) -->
        <update-interval>300000</update-interval>
    </projectlist>
</config>