Remove methods which expose internal ID

Remove the following methods with expose internal IDs
from public view

- DatastoreExtended#getDocNumericId() - Removed from public interface
- BasicDocumentRevision#getInternalNumericId() - Changed visibiity to protected

Only one question, should the getDocNumericId on BasicDatastore remain public or be made protected?
I don't think this is fetching the internal numeric ID correctly. I think you will need to admit defeat here and go back to using finding the id with ``long docNumericID = this.getDocNumericId(newRevision.getId());`` and using the result here.