Proposal to close issue i025

RX'ers:

Here is the new proposal for i025 in pseudo-schema....

<wsrm:SequenceAcknowledgement ...>
   <wsrm:Identifier ...> xs:anyURI </wsrm:Identifier>
   [ [ <wsrm:AcknowledgementRange ...
       Upper="xs:unsignedLong"
       Lower="xs:unsignedLong"/> +
   <wsrm:Final/> ? ]
   | <wsrm:Nack> xs:unsignedLong </wsrm:Nack> +
   | <wsrm:None/>]
...
</wsrm:SequenceAcknowledgement>

Essentially this just adds a new choice, <wsrm:None/>, which acts as an
explicit marker to indicate that no messages have been received.

The reason that Anish and I like this proposal so much is that it seems
to satisfy the desires of both camps:

* The people who want an EXPLICIT marker (rather than the absence of
something) to represent this case get their wish.

* The people who do NOT like the potentially confusing overloading of
sequence numbers with a 0,0 case (and all the requisite special-case
coding) get their wish of something that is clear to code.

Here is the actual proposal:

1) Amend the schema to add a third <xs:choice> element, <wsrm:None/> in
parallel with Nack and AcknowledgementRange.

2) Explain the meaning of this element in the text, i.e.
"/wsrm:SequenceAcknowledgement/wsrm:None -- no messages were received".

3) Editors to clean up the text around AcknowledgementRange (i.e. is it
really optional, etc...)

There you have it.

--Glen