Gadget listboxes will have an unique field_prefix which will guaranteed that multiple gadgets and multiple asynchronous gadgets can safely co exists in same DOM space within same HTML form without collisions.

git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@43459 20353a03-c40f-0410-a6d1-a30d3c3de9de