Caissa v1.2

• Switch regular PSQT to king-relative PSQT
• Neural network trainer optimization and improvements
• PSQT trainer refactor
• Add razoring and alpha pruning
• Tweak SEE pruning, late move prunning, etc
• Update neural network to 704x512x16x32 architecture and retrain on more data
• Fix castling move printing in non-960 mode

Regular chess improvement:

...      Caissa 1.2 (AVX2/BMI2) playing White: 204 - 26 - 144  [0.738] 374
...      Caissa 1.2 (AVX2/BMI2) playing Black: 85 - 140 - 145  [0.426] 370
...      White vs Black: 344 - 111 - 289  [0.657] 744
Elo difference: 58.0 +/- 19.6, LOS: 100.0 %, DrawRatio: 38.8 %

Chess960 improvement:

...      Caissa 1.2 (AVX2/BMI2) playing White: 154 - 51 - 121  [0.658] 326
...      Caissa 1.2 (AVX2/BMI2) playing Black: 121 - 81 - 124  [0.561] 326
...      White vs Black: 235 - 172 - 245  [0.548] 652
Elo difference: 77.5 +/- 21.3, LOS: 100.0 %, DrawRatio: 37.6 %