Media Manager: Hide 'Create Playlist' menu items until the user has uploaded audio or video.

props gcorne.
fixes #27554.

Built from https://develop.svn.wordpress.org/trunk@27841


git-svn-id: http://core.svn.wordpress.org/trunk@27675 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Restyle the image editor so it looks way less hideous.

props avryl.
see #27544.

Built from https://develop.svn.wordpress.org/trunk@27842


git-svn-id: http://core.svn.wordpress.org/trunk@27676 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Theme Installer: Remove unused variables and undesired commas.

see #27055.

Built from https://develop.svn.wordpress.org/trunk@27843


git-svn-id: http://core.svn.wordpress.org/trunk@27677 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Add braces to wptexturize() after [27839]. see #22692.

Built from https://develop.svn.wordpress.org/trunk@27844


git-svn-id: http://core.svn.wordpress.org/trunk@27678 1a063a9b-81f0-0310-95a4-ce76da25c4cd