Remove unused JS variables after [27770]. see #27013.

Built from https://develop.svn.wordpress.org/trunk@27783


git-svn-id: http://core.svn.wordpress.org/trunk@27619 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Color scheme support for the new theme installer UI.

props ryelle.
fixes #27522.

Built from https://develop.svn.wordpress.org/trunk@27784


git-svn-id: http://core.svn.wordpress.org/trunk@27620 1a063a9b-81f0-0310-95a4-ce76da25c4cd
There is no more `video-playlist` shortcode. To use video, it is now `[playlist type="video" ....]`. Also deleting core playlist styles. The `style` attribute is still supported, defaulting to `light`. Our core style support was 4-5 CSS rules. 

See #27552. Leaving open for comments and potential bugs.


Built from https://develop.svn.wordpress.org/trunk@27785


git-svn-id: http://core.svn.wordpress.org/trunk@27621 1a063a9b-81f0-0310-95a4-ce76da25c4cd