Twenty Thirteen: add Audio, Video, and Gallery Styles to editor styles. Props celloexpressions, see #27462.

git-svn-id: https://develop.svn.wordpress.org/trunk@27638 602fd350-edb4-49c9-b593-d223f7449a82
3.9-beta2


git-svn-id: https://develop.svn.wordpress.org/trunk@27639 602fd350-edb4-49c9-b593-d223f7449a82