and include that in the ZODB project.  While we're at it,
include zope.testing too, as zope.interface depends on that,
and we had copied zope.testing.loggingsupport.py into ZODB
earlier anyway (and delete that unique copy here now).

This also merges some changes made to the ZODB copy in
Zope3 back into ZODB.

update to replace ZODB 4 with ZODB 3

Added support for persistent weak references and
PersistentWeakKeyDictionary.

Add _p_invalidate() method to persistence API.  _p_deactivate() is
advisory from the cache.  _p_invalidate() is called when database
invalidates object.

Port support for getattr/setattr hacks from ZODB4.  The doctest tests
describe the new technique pretty well.

Remove unused arguments from some cPickleCache calls.

- add missing period

location of the start.py script (when it is used).

      - It is no longer necessary to symbolically link cPickle or
        ZServer. ZServer is no longer necessary at all.

This was to get a newer asynccore (or ZServers) if possible.