Improve dangerzone calculation performance

[krestenlaust]

• Right now, every time a single move has been made, either in a real move or a simulated move (all moves are simulated before being presented to the player), all pieces dangersquares are being recalculated.

Changing this approach to only update possibly affected pieces, should improve performance.

• Performance analysis results of bots, shows that UpdateDangerzones() is a major hot path. Any improvements should improve calculation speed of bots.

[krestenlaust]

I haven't had the time to look at this project, but this should probably be the highest priority when trying to improve the bot, as calculations expand considerately mid-game, and use a whole lot of computing power simply recalculating dangerzones of pieces that haven't changed.