Add details parameter to get_vt_iterator() #215

If details is True, it adds the vt dependencies as subelement with the oid. For this an expensive query to redis is necessary. The query takes about 3 seconds, which is especially expensive when only one vt must be sent. Otherwise, the dependencies are added as subelement of custom, the query will not be perfomed, and quicker response is given for a single vt.