git-rebase--interactive:  always print upstream author's $head_parent warning

This is where the band-aid fixes should've gone.  I've asked the
upstream author the significance of this warning.
automatic edits & author fixes; testing mode

Add automatic edits: Patches with the short-sha1 can be placed in the
patches directory and they will be automatically committed at an
'edit' command instead of the EDITOR being invoked

Add automatic author fixes: Like above, author & email may be placed
in a file; this will be overridden at an 'edit' command.

Testing mode: separate $upstream and $orig_head, and separate todo
list.
rebase-script:  near final version

Added commit marker fixups and author changes.

The merge madness around 87351a6 isn't easily solvable, so there are
merge markers that will hang around in the docs for a few commits.
Nothing I'm willing to do about it.
git-rebase--interactive:  first working version

Might've fixed the problem topically with the 'not_rewroted' bit and
the 'Arbitrarily' stuff.

The real fix is in the last hunk, though.  $sha1 is still 7 digits at
that point, so it never finds $rewritten/$sha1.  With that fix in
place, everything seems to work correctly.
rebase-script.txt:  first working version

- fix case where a 'branch' command commit had been reordered

- squash forgotten fixup
rebase-script.txt:  change squash to fixup, oops