Include x-ray attacks through all queens independently of the color.
When calculating attacks from rooks/bishops current master includes
x-rays through own queen. This patch includes also x-rays through
opponent queen.
Credits go to Brian who inspired for this idea
https://groups.google.com/forum/?fromgroups=#!topic/fishcooking/Z3APRYpQeMU
STC:
LLR: 2.96 (-2.94,2.94) [0.00,5.00]
Total: 41549 W: 7544 L: 7244 D: 26761
Elo 2.05 [-0.29,4.19] (95%)
http://tests.stockfishchess.org/tests/view/5a3b5fe50ebc590ccbb8bf9a
LTC:
LLR: 2.96 (-2.94,2.94) [0.00,5.00]
Total: 110010 W: 14208 L: 13739 D: 82063
Elo 1.20 [-0.27,2.55] (95%)
http://tests.stockfishchess.org/tests/view/5a3b8e7c0ebc590ccbb8bfad
bench: 5544445