Tweaking magit/diff mode to be more helpful in text editing

[Eric Abrahamsen <eric@ericabrahamsen.net>]

So I do a fair amount of writing in Org, in files that are kept in a git
repository, and I've found that, when editing large documents, it can be
nice to have the Magit Diff buffer open to one side, which I can refresh
from time to time and see the edits I've made. It's kind of an
alternative to Track Changes, etc.

I've set `magit-diff-refine-hunk' to 'all, and that helps distinguish
the actual edits from the fact that the paragraphs have been re-filled.
It's not ideal, but it's okay.

I'm currently editing someone else's (very long) document, and instead
of actually using track changes in LibreOffice, I'd much rather give him
a clean odt document exported from Org, and along with that an html
document made using diff2html or one of the other similar tools, so he
can check the edits if he wants.

What I'd really like is to find a way (either a diff algorithm or a
Magit tweak) of only showing the actual edits, not the filling. And then
to still be able to export that in a way that will allow me to give the
author a file only showing those edits.

Does anyone have any clever ideas in that direction?

Thanks!
Eric