Clarify $select behavior for stream properties

JSON Format: Stream properties requested with $select or included in the default selection are represented by their control information odata.media* . Stream properties requested with $expand or implicitly expanded are represented as a property with its value. Protocol: Services SHOULD support direct property access to a stream property's canonical URL (e.g. GET Entity(123)/Thumbnail ). The response MAY be a redirect to the media read link of the stream property if the media read link is different from the canonical URL. Note: if neither canonical URL nor media read link can be used and the stream value can only be accessed via $expand, the modeler should have used an Edm.Binary property instead.