Docpipeline working part

[mmatera]

This is another layer of improvements in the documentation system.

• Fixes some references in ImportExport documentation.
• Add and improve some docstrings and comments.
• makes that the key attribute in mathics.doc.common.DocTest be more deterministic.
• DRY __init__ routines in latex_doc subclasses.

[rocky]

I was looking at this earlier. It is good to see the LaTeX document build again.

Something to keep in mind. Chapters in the Reference part, part 1 should not be sorted by either chapter or section. In this branch, tests appear sorted by chapter in part 1. And in the LaTeX doc the sections in part 1 are also sorted.

Part of the problem here is that I removed the "sort" parameter that allows one to specify whether or not to sort chapters and sections. In master, you'll find a sort-order field for chapters for part 1 chapters.

The logic of this branch follows the older logic where tests are accessed by document sequentially and they happen to come out ordered by section and chapter. One reason it is useful to have routines to get tests by chapter or section is that sometimes we want to run just the tests or update documentation for just section or chapter. For the tests one can get direct access using a slug name.

[mmatera]

The logic of this branch follows the older logic where tests are accessed by document sequentially and they happen to come out ordered by section and chapter. One reason it is useful to have routines to get tests by chapter or section is that sometimes we want to run just the tests or update documentation for just section or chapter. For the tests one can get direct access using a slug name.

Yes, I am aware of that, but the problem is that right now, it is not working. What I tried to do is to isolate what is not working, and then see if we can fix it.

[mmatera]

superseded by #1021