[Distutils] "Specs" vs "Proposals"

pulling this idea out of the "Linux wheel support" thread, since it
deserves it's own thread...

the idea being that we should better distinguish:
1) the current packaging "Specs" (for metadata, versions, etc...)
vs
2) Proposals to change them

currently, we just have PEPs that serve both roles.

so the idea would be to:
1) house current specs at packaging.python.org... basically a document tree
that's organized by topic, not numbers and it's free of proposal
rationales, historical discussion, and transition plans etc...
2) keep using the PEP process for adjusting or adding to the specs

and assuming that approach, I raised a few "publishing" questions:
1) do we publish/render all supported versions of a certain spec, or just
the latest
2) if we publish them all, then how?  do we maintain separate documents for
distinct versions? if not, how do we do it?

--Marcus