Clean up error handling, add note about the progress made so far towards infinitely deep populates, and added comment in source letting folks know that populateDeep() is not currently implemented.
Improves error msgs in .populate()
More of the same
Normalize criteria to .populate()
(still allow 'false' though, in case that matters)
Added note about handling the marshalling of null-> [] in results from native joins.  would make it easier for adapter implementors