In `WPPlaylistView::ended()`, at the end of a playlist, set the index to `0` and call `->setCurrent()` instead of `->loadCurrent()` so that the first track is properly highlighted.

Fixes #28428.

Built from https://develop.svn.wordpress.org/trunk@28649


git-svn-id: http://core.svn.wordpress.org/trunk@28467 1a063a9b-81f0-0310-95a4-ce76da25c4cd
In the spirit of [27622], add a few CSS rules to ensure that videos will be responsive, regardless of theme.

Props Funkatronic.
Fixes #28414.

Built from https://develop.svn.wordpress.org/trunk@28650


git-svn-id: http://core.svn.wordpress.org/trunk@28468 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Add oEmbed support for TED talks.

props pdclark.
fixes #28285.
Built from https://develop.svn.wordpress.org/trunk@28651


git-svn-id: http://core.svn.wordpress.org/trunk@28469 1a063a9b-81f0-0310-95a4-ce76da25c4cd