Revert "Drop periodicity, as it does not support exact month additions."

This reverts commit 1ec72363.

product/ERP5/Document/SubscriptionItem.py

@@ -39,7 +39,6 @@ from Products.ERP5.mixin.rule import MovementGeneratorMixin
 from Products.ERP5.mixin.periodicity import PeriodicityMixin
 from Products.ERP5Type.UnrestrictedMethod import UnrestrictedMethod
 from Products.ERP5Type.Base import Base
-from Products.ERP5Type.DateUtils import getNumberOfDayInMonth
 
 from zLOG import LOG
 
@@ -303,9 +302,7 @@ class SubscriptionItem(Item, CompositionMixin, MovementGeneratorMixin, Periodici
         current_date = start_date
         id_index = 0
         while current_date < stop_date:
-          # XXX-Luke: Periodicty usage was dropped as real month additions shall
-          # be supported, when periodicity floors result to given period precision
-          next_date = current_date + getNumberOfDayInMonth(current_date)
+          next_date = self.getNextPeriodicalDate(current_date)
           if next_date > stop_date:
             next_date = stop_date
           generated_movement = newTempMovement(self, 'subscription_%s' % id_index)