Update menu bars as per #1166

Closes #1166.

Note that there's still a TODO in the code at https://github.com/mysociety/pombola/blob/dedb5cbd353579a06839ba8d2eb4dde92df8f90d/pombola/south_africa/templates/menu_entries.html#L60 - Is that still really a TODO, or can it be removed?

Closes #1166