Display consistent preview links for drafts.

props mordauk.
fixes #28350.
Built from https://develop.svn.wordpress.org/trunk@28920


git-svn-id: http://core.svn.wordpress.org/trunk@28719 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Force a separator in get_wp_title_rss() if it was inadvertently filtered out by the theme.

fixes #22362.
Built from https://develop.svn.wordpress.org/trunk@28921


git-svn-id: http://core.svn.wordpress.org/trunk@28720 1a063a9b-81f0-0310-95a4-ce76da25c4cd