Issue CORE-122: Normative References

Sections 1.9 and 1.10 of PR Draft 02 contain References, divided into
Normative and Non-Normative sections.

According to the TC Process:
  "Normative Reference" means a reference in a specification to an
  external document or resource with which the implementer must
  comply, in order to comply with a Normative Portion of the
  specification.

(Note that any "Normative Portion" of the specification may be
optional; but IF IMPLEMENTED, it must conform to the specification and
relevant Normative References.)

I propose to add normative references to HTTP 1.1 (RFC 2616) and SMTP
(RFC 2821), as those bindings are specified in the Core.  Are any
other references missing or miscategorized?

--Pete
Pete Wenzel