(RNFR now returns 350 as status code instead 250)

http://mail.zope.org/pipermail/zodb-dev/2005-December/009662.html
Basic symptom was lots of conflict in sessions.
Unit test included.

  Update Five to bugfix release 1.3.1.

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in some unittests (if necessary we need to restablish the hacks
in a saner way)