Annotation specification:
(: Responsible for performing the login of an user, see sec:authenticate and sec:login functions :) in the security module:) <br />
'''%sec:authenticate()''' <br />
(: The default authentication fallback function. The function must not have any arguments :) <br />
(: relevant information like the current username might be available through additional xquery function in the security module :) <br />
'''%sec:authentication-fallback()''' <br />