Two PRs merged into devel

[Edward K. Ream]

Leo's "devel" branch now contains two significant PRs:

PR #3838 updates developer scripts that build and test Leo. The (newly revised) info issue #2867 lists these scripts. All these scripts are now Python scripts. How did we ever live without them?

PR #3838 improves the annotations in leoTokens.py (Leo's beautifier) so that mypyc can compile it.  My tests show the compiled version is about twice as fast as the pure Python version. Compiling leoTokens.py is optional:

cd leo-editor

python -m mypyc leo/core/leoTokens.py --strict-optional

Summary

- PR #3838 helps all developers test their code.

- PR #3838 doubles the speed of Leo's beautifier.

Both PRs change Leo's codebase significantly. Please report any problems.

All questions and comments are welcome.

Edward