Always localize `mediaelement` when passing settings to the page via JSON. `wp-mediaelement` only gets triggered for audio and video shortcodes, playlists need the path passed to the page as well, as they don't enqueue `wp-mediaelement`.

See #27509.


Built from https://develop.svn.wordpress.org/trunk@27734


git-svn-id: http://core.svn.wordpress.org/trunk@27571 1a063a9b-81f0-0310-95a4-ce76da25c4cd