Clarify Requesting Changes to entity sets that include Stream properties

This relates to the procotol spec (2013-03-12) section 10.3 Requesting Changes.

If a client requests an entity set with change tracking enabled, then Stream contents will never be included inline (Streams have to be separately fetched).

But it would be good to clarify that if the contents of some Stream properties have changed, then the client (via a delta link) asks for changes to an entity set, they will receive changed entities for any entities whose stream properties have had their content changed.