new issue: remove redundant MUST obey xrefs

RFC 2616 sections 9.5 (POST) and 9.6 (PUT) have the following
useless waste of bits

    POST requests MUST obey the message transmission requirements set  
out
    in section 8.2.

    See section 15.1.3 for security considerations.

and

    PUT requests MUST obey the message transmission requirements set out
    in section 8.2.

respectively.  They can be safely deleted without changing HTTP.

Section 8.2 is not specific to PUT and POST.  Likewise, a content-free
forward pointer to just one of the many subsections on security
consideration is a total waste of brain cells.

Those are just two examples of what can only be described as a
spaghetti style of content-free cross-references within the spec
that make it very hard to read.  They should be removed in general
at the editors' discretion.

....Roy