About mass changes to Leo's code base

[Edward K. Ream]

I want to emphasize here that there is no great urgency to making any large-scale changes to Leo's code base.  There are much more important issues to attend to.  Having said this, here are my present plans:

1. I am happily converting to f-strings as I go along.

I probably will merge the fstring branch into devel, after at least one thorough review of the diffs before doing this.

I don't want to defer the decision much longer: it's inconvenient to be merging into long-lasting branches.

2. I have no intention of using black on Leo's code base.  Not now.  Not ever.

3. I have just begun work on #1266 (orange).

The new work contains a rewrite of the code that compares the "before" and "after" parse trees. It's much better than the previous code. I'll merge this into devel soon.

The rest of #1266 is experimental. I'll defer this project if it is going to take more than a few days.

Summary

I have gotten a bit sidetracked with code formatting issues.  I'll give myself a few more days to wrap things up.

Edward