Calls to items_data() now return Item instances
Calls to items_data() now return Item instances

Item instances are currently little more than placeholders for key/value pairs. Calling Item.attribute for a nonexistent attribute will return None instead of raising an AttributeError. This could also be achieved by subclassing dict and defining a custom __getitem__ function to return None.

DrGo/pyzotero,urschrei/pyzotero