[AD] Yield contacts in original ID order batching
[AD] Yield contacts in original ID order batching

The batching code was not yielding contacts back in the original order of
their IDs which is the order created by any OrderBy() calls. Fixes #3.

orand/Xamarin.Mobile,xamarin/Xamarin.Mobile,nexussays/Xamarin.Mobile,xamarin/Xamarin.Mobile,haithemaraissia/Xamarin.Mobile,moljac/Xamarin.Mobile