combined proposal for issues 8180, 8299, and 8302

To summarize the positions on the basic issues:

8180:

    Yes, resource representations can be "empty", i.e. "have no value".
    Empty resources are created by supplying a <wst:Representation/> in
    Create. The existence of an empty resource is indicated by a Get
    that returns a <wst:Representation/>. Resources can be "made empty
    (i.e. have their representation removed) by Put-ing a
    <wst:Representation/>.

8299:

    The ambiguity between representation and extensions has been removed
    by the introduction of the wst:Representation element. The XML
    element inside a wst:Representation is the representation. Anything
    outside the wst:Representation element (and in a different namespace
    that WS-T) is an extension. This is described without complicated
    language on the optionality of representation etc.

8302:

    I believe this is significantly clearer and more straightforward
    than previous versions. The use of the "implicit Get" operation is
    described in straightforward way that allows for it to be used in a
    multitude of situations but does not require services to perform
    onerous tasks such as transmitting very large messages in response
    to very large requests.

- gp