connection can be holding on to an object with references to an object
that has been recently garbage collected.  When the object is unghosted in
the reference-holding thread, the storage cannot find the oid (because it's
out of storage due to gc).  We work around this by turning KeyErrors that
we believe are due to this scenario into ConflictErrors.

  - Wire up security policy selection machinery to ZConfig (note that the
    'C' policy is currently borked, but should be fixed very soon).

As the earlier comment indicated, this storage does not support
multiple revisions.  The RevisionStorage tests changed to require
revision support, so the tests now fail.  This might be the right
long-term strategy, but it needs a little thought.

BaseStorage._tid.

consistent with changes in ZODB 3.3.

contains files related to the TemporaryStorage ZODB storage.

These files used to be in the TemporaryFolder Product, but have been
moved to solve issues which resulted from premature imports during startup
caused by import of the TemporaryFolder package
by the configuration machinery (particularly the premature import of
Globals, which pulls in almost every Zope package) during database setup.