GitLab

Introduce a new interface expandable_item which extends expandable and add this
functionality, and provides default implementation that maybe have to be
extended for some specific subscription items usages.


git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@44254 20353a03-c40f-0410-a6d1-a30d3c3de9de