Amended proposal for i059

In line with the discussion on Monday's call and the email I just sent
out, here is an amended version of the proposal for UsingAddressing.  My
additions and changes are shown in green.  Deleted text has been quietly
omitted.  Points of interest:

    * I have substituted "response endpoint" for [reply endpoint] and
      wsa:replyTo, and defined "response endpoint" as "[reply endpoint]
      or [fault endpoint] as the case may be".
    * I have tried to consistently use "inbound message" for "request"
      and "outbound message" for response, in line with WSDL use of "in"
      and "out" and in contrast to "request" and "response" in the SOAP
      and HTTP context.
    * In combining my proposal with the existing proposal, I noticed
      that much of the text in each was actually independent of which
      version of SOAP is in use.  I have combined these and boiled them
      down a bit, shortening both in the process.
    * I completely removed the text about anonymous being "required"
      etc. from the SOAP section.  I believe this is in line with Marc's
      comment about repeated text.  The first section discusses /when/
      the anonymous URI can appear, the following sections discuss what
      that means, and as far as I can tell the two are independent.
    * All this notwithstanding, the core of the original proposal for
      SOAP1.1/HTTP is basically intact.  In generally, I believe this
      latest version has essentially the same semantics as the previous
      one, but is briefer, (hopefully) clearer, and applicable to both
      SOAP 1.1 and SOAP 1.2

As always, comments are welcome.