The rough fast score estimation used for playout is currently also used for MCTS and actual win-calculation

[kalliduz]

For playouts it's fine to use a fast algorithm that only counts stones and their direct neighbours, since the playout normally continues until everything is settled in a trivial way.

Unfortunately, there is no exact score calculation, which should be used after two play pass in the actual game.

It should also consider liberties that are only surrounded by other liberties, so we need some advanced distance/direction calculation for these fields.

This also leads to faulty decisions of pass moves in the tree. So we need to apply it there too, after two player passed in a node.