Boudica retirement ability shows through fog

## Summary

When selecting the great general Boudica, white outlines appear adjacent to barbarians to signify use of their retirement ability. The retirement ability allows you to capture adjacent barbarians. These white outlines are being shown for all barbarians when you do not have vision of the area.

## Expectation

White outlines appear next to barbarians that you can see.

## Actual

White outlines appear next to barbarians on revealed territory which you have no vision of.

### Example

http://steamcommunity.com/sharedfiles/filedetails/?id=1228404158

The issue does not name a file, test, or entry point. Start by locating the Lua code that renders Boudica's retirement ability outlines, then verify that outlines are shown only for visible barbarians and not for barbarians in revealed but currently unseen territory.

Written by the indexing model from the issue text.