HACK: extend product.product name_search() for x_sysmo_barcode

This should be properly done in an extension, but was easier to add to
the core product.product code right now :/

addons/product/product.py

@@ -1130,6 +1130,8 @@ class product_product(osv.osv):
                 ids = self.search(cr, user, [('default_code','=',name)]+ args, limit=limit, context=context)
                 if not ids:
                     ids = self.search(cr, user, [('ean13','=',name)]+ args, limit=limit, context=context)
+                if not ids:
+                    ids = self.search(cr, user, [('x_sysmo_barcode','=',name)]+ args, limit=limit, context=context)
             if not ids and operator not in expression.NEGATIVE_TERM_OPERATORS:
                 # Do not merge the 2 next lines into one single search, SQL search performance would be abysmal
                 # on a database with thousands of matching products, due to the huge merge+unique needed for the