Because there are problems with PropertyExistence, define both
message_property_not_set and message_no_such_property. (see this thread
http://mail.nexedi.com/pipermail/erp5-dev/2008-May/001900.html )


git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@21744 20353a03-c40f-0410-a6d1-a30d3c3de9de