Add paging capability to iterate method

Hi Jens, I am with GreatVines in Portland, USA. I used IDBWrapper to create a mock implementation of the Salesforce SmartStore (a database component in the Salesforce Mobile SDK). Since SmartStore is able to "paging" with a configurable page size, we added this capability to the IDBWrapper's iterate method. Maybe this feature could be added to IDBWrapper.

Peter