Clean up the sticky menu and responsive tweaks JS:
- More descriptive names.
- Share cached jQuery elements.
- Fix re-enabling of touch events on the admin menu.
- Fix disabling/enabling of UI Sortable.
Props tollmanz, props sanchothefat, see #26086, fixes #26088.
Built from https://develop.svn.wordpress.org/trunk@26402


git-svn-id: http://core.svn.wordpress.org/trunk@26302 1a063a9b-81f0-0310-95a4-ce76da25c4cd