AuthElement Constructor

Used when an ad-hoc authelement is to be used, e.g. in connection with request for rights for a user. Important that this type of constructor is not used for an existing id (id> 0) if the object (authelement) is subsequently to be saved in db. This will mean that new (useless) appstrings will be created in db! However, this is not a problem for just this particular class since there a sawing method for AuthElement does not exist at all!