[Skills] Upgrade demon tracker hopefully without making it totally overpowered

[Klapaucius]

Make the range adjustable, and have the mp cost scale with range as radius*2.

The upgrade skill gives a small mp discount and increases the max range.

At this cost, current basic would be 6 mp, upgraded would be 8 mp for the larger square, but you could also do 2x2 for 4 mp, or just the square you're on for 2 mp.

This would mean better ability to track down the demon you pinged with your initial 5x5, and more tolerable mp cost for the triangulation component of the tracking