Add missing Dashicons classes to Network Admin menu, see #26630.

git-svn-id: https://develop.svn.wordpress.org/trunk@27444 602fd350-edb4-49c9-b593-d223f7449a82
At long last, a first pass at bringing the image editor into the media modal. props gcorne, DH-Shredder, tomauger. see #21811.


git-svn-id: https://develop.svn.wordpress.org/trunk@27445 602fd350-edb4-49c9-b593-d223f7449a82