Restore the ability to break-up partnerships with only 1 cat present

[Sara Franco]

I'd prefer if the breakup happens automatically upon ownership change event.
And maybe adding a small check when the kitty contacts the server if Partner is flagged in menagerie or has no record (if they delete the actual record from the database) the breakup happens too.

But the ownership change breakup may be bad if you pass kitties to alts sometimes...