new Firefox doesn't allow "tabs on top"?

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http://www.linuxquestions.org – In previous Firefox versions, you could check or uncheck "Tabs on Top" to specify whether your tabs bar would go above your URL bar or below the bookmarks toolbar. I unchecked it because I prefer the tabs at the bottom. That setting appears to be no longer available in Firefox 22. Has it been moved elsewhere in the menus, or is there another way to do it? (HowTos)