added grouping reference in property sheet

git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@3301 20353a03-c40f-0410-a6d1-a30d3c3de9de

product/ERP5/PropertySheet/Movement.py

@@ -74,6 +74,10 @@ class Movement:
             'acquisition_depends'           : None,
             'alt_accessor_id'               : ('_categoryGetOrderRelativeUrl', ),
             'mode'        : 'w' },
+	{   'id'          : 'grouping_reference',
+            'description' : 'A reference which allows to unify multiple objects',
+            'type'        : 'string',
+	    'mode'        : 'w' },						     
     )
 
     _categories = ('order', Expression('python: portal.getPortalVariationBaseCategoryList()'))