selectors4 API hooks section (was Re: Proposed agenda)

This message is in reply to
https://lists.w3.org/Archives/Member/w3c-css-wg/2016OctDec/0130.html
which I don't quote here because I'm moving the conversation from
w3c-css-wg to www-style, since I'm changing the
spec-publication-process discussion to a technical discussion.


I made the edit requested:
https://hg.csswg.org/drafts/rev/b3e73b31460c so now the API Hooks
section is basically rewritten (other than the two hooks for
parsing), and needs careful review:
https://drafts.csswg.org/selectors/#api-hooks

I'm particularly concerned that:
 * some of the scoping stuff may be wrong, although I tried to
   preserve what the old version was doing.  (I did add one issue
   where I thought it was inconsistent with what the other section
   of the spec says.)
   
 * some of the pseudo-element stuff may be wrong, but I think fixing
   that might require a clearer model of how pseudo-elements work,
   and in particular when they are created.

I also noted in the changes section that a term that was present in
the editor's draft for other specs to link to is now no longer
present:
  https://drafts.csswg.org/selectors/#evaluating-selectors
with the links to that term now pointing to the changes section.
(I'm a little worried about doing that since the relevant bit of the
changes section might go away...)

-David

-- 
𝄞   L. David Baron                         http://dbaron.org/   𝄂
𝄢   Mozilla                          https://www.mozilla.org/   𝄂
             Before I built a wall I'd ask to know
             What I was walling in or walling out,
             And to whom I was like to give offense.
               - Robert Frost, Mending Wall (1914)