Refactoring numbers

[Rob Beezer]

"I've wanted to do this for years!"
- Mott the Hoople, All The Young Dudes, 1972

And indeed I have been *trying* for years. Major refactoring of the numbering
code is finished. Done right, nobody will notice. The production of numbers by
PreTeXt is now
(a) much more natural as an XSL process,
(b) matches what LaTeX would do naturally,
(c) free of some existing bugs in certain edge cases,
(d) faster,
(e) soon supporting "open problems", and
(e) still not perfect.

There are remaining real problems with numbered items in a division's
#introduction or #conclusion, even if these have improved somewhat. I will
blame this on LaTeX not doing well with a #conclusion. More on this in the
months ahead, but it is likely that we will be taking more active measures to
discourage "heavy" #introduction and #conclusion.

Many more details at the links below. Questions and comments to
pretext-support or pretext-dev.

Rob

https://github.com/PreTeXtBook/pretext/pull/2904

https://github.com/PreTeXtBook/pretext/issues/2905

https://github.com/PreTeXtBook/pretext/issues/2906