Change 'This post is password protected' to 'This content', for the benefit of custom post types.

props MikeHansenMe.
fixes #23603.


git-svn-id: https://develop.svn.wordpress.org/trunk@25582 602fd350-edb4-49c9-b593-d223f7449a82
Return false in update_metadata() and update_metadata_by_mid() when the DB query fails.

props leewillis77.
fixes #24933.


git-svn-id: https://develop.svn.wordpress.org/trunk@25583 602fd350-edb4-49c9-b593-d223f7449a82