Add jshintrc to qunit.

props jorbin.
see #25187.

Built from https://develop.svn.wordpress.org/trunk@25992


git-svn-id: http://core.svn.wordpress.org/trunk@25925 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Inline documentation for hooks in wp-admin/nav-menus.php.

Props pauldewouters for the intial patch.
Fixes #25528.

Built from https://develop.svn.wordpress.org/trunk@25993


git-svn-id: http://core.svn.wordpress.org/trunk@25926 1a063a9b-81f0-0310-95a4-ce76da25c4cd