LP#1378829 Fix long overdue override permission

LP#1378829 Fix long overdue override permission

Fix override permission used when checking in a copy that is "long
overdue".

The existing permission was incorrectly created with a code of
COPY_STATUS_LONGOVERDUE.override, while the event thrown requires a
permission with a code of COPY_STATUS_LONG_OVERDUE.override

This commit updates the seed data and a few references to the
old/incorrect permission in documentation, and also includes an
upgrade script designed to accommodate the various likely ways in
which sites may have already locally addressed this issue.

A simple pgtap test is also included.

Signed-off-by: Jeff Godin <jgodin@tadl.org>