[Swan-commit] Changes to ref refs/heads/master

[D. Hugh Redelmeier]

New commits:
commit 717fb8a799868a832fc59da86a777085b7cff5fa
Author: D. Hugh Redelmeier <hugh at mimosa.com>
Date:   Thu May 23 13:03:58 2019 -0400

    pluto: virtual.c: tidy
    
    - add comments to capture what I've understood
    
    - correct mistaken comments
    
    - reduce scope of autos
    
    - simplify while retaining (possibly defective) logic
    
    - resove some ???, add some ???
    
    More work is needed.