When autosaving a new post for the first time after a title was typed, cancel the autosave if the user is submitting the form. (Includes a precommit fix for customize-controls.css.) Props Nessworthy, davidmarichal, fixes #27657

git-svn-id: https://develop.svn.wordpress.org/trunk@27951 602fd350-edb4-49c9-b593-d223f7449a82