the onwrite handler created an "empty" record with no field value whatsoever, which'd blow up in the py evaluator. As during creation (edition of a record where all fields are empty) create a record where all fields are set to ``false`` so rendering works correctly, and wait for content refresh to get correct data. Also added a test for @on_write bzr revid: xmo@openerp.com-20121112150526-vrr66ms95qbuoped