UI for Tabs

[Jordan Gowing]

Perhaps it's just me, but I think that the skeuomorphic design of individual tabs would benefit from an update to match the new Sierra "tabs" for different workspaces. In addition to providing uniformity (across the entirety of the Mac OS; cf. Safari's use of tabs for another example) and a cleaner, more modern look, it could save some essential screen real estate for those with smaller screens.