Switch to a CSS comment in gallery_shortcode() to avoid breaking markup when the shortcode is used inside an HTML comment. props mark-k, aaroncampbell. fixes #23787.

git-svn-id: http://core.svn.wordpress.org/trunk@24329 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Compress scripts/styles: 3.6-beta3-24330.

git-svn-id: http://core.svn.wordpress.org/trunk@24330 1a063a9b-81f0-0310-95a4-ce76da25c4cd