[LinuxPPS] [PATCH 02abc/12] Split up...

[George Spelvin]

I split the previous patch 02/12 into three parts to make it easier to
review.  They don't produce quite the same end-state, as I deleted the
unnecessary if (!uarg) tests, but it doesn't seem worth reposting
the whole series for that just yet.

As its own commit comment says, the third one could probably use some
work, but I didn't want to make significant changes here; it's mostly
just a split-up.

(Footnote: git-gui was a great help here, but is there some way to
select multiple lines to stage/unstage?)