When creating audio and video MCE views, listen to the players within each iframe to capture the "play" event. When a player plays, pause the players in every other iframe sandbox.

Fixes #29384.


git-svn-id: https://develop.svn.wordpress.org/trunk@30642 602fd350-edb4-49c9-b593-d223f7449a82
Add an entry to the changelog for the `wp_editor_expand` hook denoting that the `$post_type` parameter was added in 4.1.0.

See #30458.


git-svn-id: https://develop.svn.wordpress.org/trunk@30643 602fd350-edb4-49c9-b593-d223f7449a82