Move shared code in PostItemView and PostDetailView to a parent class

Move shared code in PostItemView and PostDetailView to a parent
class (PostItemView). Renaming PostItemView to PostLIstItemView.

Cleaner handling of post delete on a detail view: use history.back()
rather than always redirecting to views/list.
Wire up publish/unpublish button in post list and post detail views

Add events for publish and unpublish post. Bind these to js- classes
and add the
classes to our template.