Contrary to Europe/Paris, Zope performs automatic DST calculation in US/Eastern
timezone, which caused infinite loop in Alarm.getNextPeriodicalDate.

Reenable testOpenOrder.testPeriodicityDateList (still failing though),
and create a testOpenOrder.testPeriodicityDateListUniversal to show that it
works with UTC times.

git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@31657 20353a03-c40f-0410-a6d1-a30d3c3de9de