Marked brackets range on scrollbar

- VSCode Version:1.12.1 - OS Version:Linux Steps to Reproduce: 1. Click on the code, inside the brackets. 2. Marked brackets range on scrollbar. Internal bracket marked with a main color. External brackets in gray (all). Same with more nesting brackets.  3. As soon as one brackets, it's just the main color.  This will be very useful. Particularly for longer code blocks, so that you can easily see where it ends and where it starts.