patches: patch OFS to bring back old __repr__
When updating persistent to >= 4.4 __repr__ of zope objects display
information about ZODB connection but it's more useful to have
information about the acquisition chain at this level.
This happens because persistent.Persistent.__repr__ is used instead of
OFS.SimpleItem.Item.__repr__ (as of zope 2.13 ).
One notable case was proxy field error messages, it was supposed to include the path of the proxy field in the error message. This one is fixed by fixing the MRO so that persistent.Persistent does not appear first.