*create new script to set value of reference
*modified validator so that EAN13 code is only completed when the specific properties exist
*modified script so that it searches for item reference before creating the item

git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@27913 20353a03-c40f-0410-a6d1-a30d3c3de9de