Clarify ordering of instance annotations in [ATOM] and [JSON]

annotations logically come as part of the thing that they are annotating. Some annotations are required in order to correctly interpret the thing being annotated (i.e., odata.type), while other annotations may not be available until the thing being annotated is materialized (i.e., odata.nextlink).

In order to support efficient streaming, OData should define for [ATOM] and (streaming) [JSON] that annotations must immediately precede properties, and must precede or follow entries, links and feeds.