Look around scrolling within sight range

I tried to make the look around scrolling work better with circular distances, mainly because not every visible tile can be examined using direction keys. Some things that will improve or change with this:

- All positions within sight range can be visited by scrolling with direction keys.
- You can not scroll out of view with direction keys anymore. Scrolling is capped to the edges of sight range, including fast scrolling.
- When out of sight and you start to scroll to a new position out of sight you start scrolling again at the nearest edge of sight.