Post locks:
- When a post is locked, ensure the 'Go back' button doesn't reload the same screen. If no referrer, change the button from 'Go back' to 'Go to All Posts'/'Go to All Pages' etc.
- Remove restriction on checking locks only for posts.
See #23697.



git-svn-id: https://core.svn.wordpress.org/trunk@24408 1a063a9b-81f0-0310-95a4-ce76da25c4cd