Keep the Nav Menu walker from blowing up the layout on empty-titled items.

fixes #23254. props cais, SergeyBiryukov.

git-svn-id: https://core.svn.wordpress.org/trunk@24560 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Compress scripts/styles: 3.6-beta4-24560.

git-svn-id: https://core.svn.wordpress.org/trunk@24561 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Instead of saying that scaling up images will result in fuzzy images, just say that it's not supported (because it isn't).

fixes #23713. props ericlewis.

git-svn-id: https://core.svn.wordpress.org/trunk@24562 1a063a9b-81f0-0310-95a4-ce76da25c4cd