copies: handle more cases where a file got replaced by a copy
This patch fixes the changeset-centric version in a pretty
straight-forward way. It fixes it to automatically resolve the
conflict, which is better than resulting in a modify/delete conflict
as it was before b4057d001760 (merge: when rename was made on both
sides, use ancestor as merge base, 2020-01-22).
I'll leave it for later to test and explicitly handle cases where
files have been renamed to the same target on different sides of the
merge.
Differential Revision: https://phab.mercurial-scm.org/D8653
Mercurial's documentation is kept in reStructuredText format, which is
a simple plain text format that's easy to read and edit:
http://docutils.sourceforge.net/rst.html
It's also convertible to a variety of other formats including standard
UNIX man page format and HTML. You'll need to install Docutils:
http://docutils.sourceforge.net/
Use the Makefile in this directory to generate the man and HTML pages.