Amend commit 434cd832 to error when the db history in archive.info and backup.info do not match.
The Perl code would attempt to reconcile the history by matching on system id and version but we are not planning to migrate that code to C. It's possible that there are users with mismatches but if so they should have been getting errors from info for the last six months. It's easy enough to manually fix these files if there are any mismatches in the field.
Contributed by Cynthia Shang.