Adjust pawn value based on promotion type

Adjust pawn value based on promotion type

shatranj STC
LLR: 2.98 (-2.94,2.94) [0.00,10.00]
Total: 3802 W: 386 L: 311 D: 3105
http://www.variantfishtest.org:6543/tests/view/5ed4336b6e23db36d55f2cf9

shatranj LTC
LLR: 2.97 (-2.94,2.94) [0.00,10.00]
Total: 2686 W: 230 L: 164 D: 2292
http://www.variantfishtest.org:6543/tests/view/5ed81b436e23db36d55f2d3b

sittuyin STC
LLR: 2.98 (-2.94,2.94) [0.00,10.00]
Total: 1820 W: 168 L: 105 D: 1547
http://www.variantfishtest.org:6543/tests/view/5ed73f8b6e23db36d55f2d19

sittuyin LTC
LLR: 2.96 (-2.94,2.94) [0.00,10.00]
Total: 2435 W: 158 L: 97 D: 2180
http://www.variantfishtest.org:6543/tests/view/5ed81bb86e23db36d55f2d3e