patches/States.py: add addPossibleTransition which acts as an universal method...

patches/States.py: add addPossibleTransition which acts as an universal method for both types of workflow.

product/ERP5Type/patches/States.py

@@ -42,6 +42,10 @@ def setProperties(self, title='', transitions=(), REQUEST=None, description='',
     if REQUEST is not None:
         return self.manage_properties(REQUEST, 'Properties changed.')
 
+def addPossibleTransition(self, tr_ref):
+    self.transitions = self.transitions + (tr_ref,)
+
+StateDefinition.addPossibleTransition = addPossibleTransition
 StateDefinition._properties_form = _properties_form
 StateDefinition.getAvailableTypeList = getAvailableTypeList
 StateDefinition.setProperties = setProperties