Implement subscriber hooks.
Thinking on this some more, hooks may be pointless. At this point, only admins are allowed to add/edit items. There seems to be no need to add item edit hooks there (like a captcha for instance) since it is admin only.
In addition, there is currently no need to view items individually, so there probably is no need to implement display hooks on a per item basis.
leaving the ticket open for now, but at this point probably won't implement.
add subscriber hook capability for item display only. closes #2. also…
… fix parent category link from user item display view.