I really liked the unobtrusive tabbar in 0.4.x as
compared to 0.5. Specifically, the border between the
tab bar and the main window and the borders that
surround each tab are thicker and more noticeable. It
would be awesome if there was a directive to set the
tab bar border's size. I would also like to choose a
separate color for the tab bar borders as opposed to
using the foreground color.