Revert r24785 partially (Stop hiding modified workflow subobjects), because when the root object of a workflow is modified, the entire workflow is recreated: all subobjects are discarded and must be reinstalled.

git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@24832 20353a03-c40f-0410-a6d1-a30d3c3de9de