Optionally restore float behavior

In the previous major version, the menu bar would float at the top of the window. That is, the menu bar was always visible, even when the browser was scrolled down the page. That was a feature—for me, anyway—and I hope it can be restored.

I figure it should be an option, as not everyone liked it. And, it would need a small tweak. In the previous version, the floating-ness meant that the menubar overlaid the top few millimeters of the page layout, and it didn't look very good. For someone trying to make the site as appealing as possible for the sake of reluctant users, that was a significant issue. To avoid that, perhaps it would be good to inject a non-floating region of the same size. That way, when the page is scrolled to the top, the floating menubar would overlap the blank area, leaving the page layout unmarred.