more content.

fleshed out discussion of call correspondence.

added initial work on standard high-level 1:n Alloc.

Moved note-to-self on Reap support to an unresolved question.
some renames.  added ToC.
added wheres the beef section.
Wrote rest of a (pair of) paragraphs that I had just left as a sentence fragment before.
Various revisions, largely to presentation.
Attempted to do some cleanup on the RawAlloc API.