The trash button does not allow anymore to remove object from the database when there is a workflow associated to this object (excepted for edit_workflow).
In such case, there must be a workflow transition called "delete_action", which changes the state of the object to "deleted".

git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@10004 20353a03-c40f-0410-a6d1-a30d3c3de9de