Add a compatibility layer in `wp-playlist.js` to avoid VM errors from MediaElement's plugin bridge in the TinyMCE views for playlists by suppressing playback for files whose mime-type is not supported in the user's browser natively.

This is similar to how audio and video shortcodes are handled: file types are whitelisted for native playback.

See #27892.


Built from https://develop.svn.wordpress.org/trunk@28171


git-svn-id: http://core.svn.wordpress.org/trunk@28002 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Properly account for text overflow in `.wp-playlist-caption` by adding `display: block`.

Props celloexpressions.
See #27923.


Built from https://develop.svn.wordpress.org/trunk@28172


git-svn-id: http://core.svn.wordpress.org/trunk@28003 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Support RTL properly when displaying playlists.

Props SergeyBiryukov.
See #27924.


Built from https://develop.svn.wordpress.org/trunk@28173


git-svn-id: http://core.svn.wordpress.org/trunk@28004 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Add `calc()` rules for `max-width` of playlist caption.

Props celloexpressions.
See #27923.


Built from https://develop.svn.wordpress.org/trunk@28174


git-svn-id: http://core.svn.wordpress.org/trunk@28005 1a063a9b-81f0-0310-95a4-ce76da25c4cd