Add a border around the tabs

Sometimes I want to use the horizontal tabs as primary or secondary navigation, and I always end up adding a rectangle behind the tabs themselves so that the tab control borders connect to the header and body boxes.

So two options would be good:
1. toggle a "tray" around the tabs. This would be a separate border that goes around the tabs and connects to the tab panel. Optionally it could have it's own background color, distinct from the panel color.
2. toggle the visibility of the panels. Sometimes I am doing a more complex layout in the body, and I just want to represent the tabs without the overhead of the panel.