RSM improvments/refactoring: - a warning message is displayed if maxItems == 0 in getItems, and an empty list is returned in this case - use the new container.ItemData instead of doing tuple (un)packing - the list of ItemData => list of domish.Element conversion is done at the end of the workflow - rsm request is checked in self._items_rsm directly - better handling of Response.index in _items_rsm - itemsIdentifiers can't be used with RSM (the later will be ignored if this happen) - don't do approximative unpacking anymore in _items_rsm - countItems and getIndex have been refactored and renamed getItemsCount and getItemsIndex, don't use query duplications anymore - cleaned query handling in getItems - /!\ mam module is temporarly broken

create table callbacks (
    service text not null,
    node text not null,
    uri text not null,
    PRIMARY KEY (service, node, uri)
);