Cluster tracking

More nice looking technical stuff. Here you can see the movement of different clusters and how they are assigned together every step. This is how the AI will keep track of how the enemy moves and if the clusters split up or merge. Currently this does not depend on how the player has set the groups. I didn’t want that to affect the behaviour of the AI because it could have some unwanted effects, like the player having to think how the groups should be set so that the AI reacts poorly. But that info is not going to be hidden from the opponent, I think. I might use it to visualize the enemy army for the human player.