Feature: Show the location of off-window Find Highlights with indicators in the vertical scroll bar.

The feature is hard to describe, but it's the same as what happens when using "Find..." in Chrome, or "Mark Occurrences" in Eclipse.

* It's basically a way of showing the location of Find matches that aren't visible in the current scroll view. (i.e. Matches that require the user to scroll up or down to see.)

* Chrome and Eclipse does this by rendering coloured bars to indicate the relative position of each match in the vertical scroll bar.