Redirect to default view

Now the redirect for locked objects is to obj.absolute_url().
This is a problem when you try to activate lockingbehavior on an Image (I tryied with a plone.app.contentype dexterity Image CT) because the absolute_url is the image and not the view "@@view"

In this pull request I add the default_view to the redirect url making it become object.absolute_url/@@default_view.