For now, special cases are handled in _edit methods in many
documents : DeliveryLine, DeliveryCell ... Ideally, to prevent code
duplication, it should be handled in a _edit method present only in
Amount.py


git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@5132 20353a03-c40f-0410-a6d1-a30d3c3de9de