Bread Engine 0.0.9

Updated readme, tweaked late move reductions, refactored some code and added check extensions. Bread Engine 0.0.9 is around 45 elo stronger than version 0.0.8.

Score of bread_engine_0.0.9 vs bread_engine_0.0.8: 311 - 223 - 164 [0.563] 698
... bread_engine_0.0.9 playing White: 203 - 79 - 67 [0.678] 349
... bread_engine_0.0.9 playing Black: 108 - 144 - 97 [0.448] 349
... White vs Black: 347 - 187 - 164 [0.615] 698
Elo difference: 44.0 +/- 22.7, LOS: 100.0 %, DrawRatio: 23.5 %
SPRT: llr 2.95 (100.2%), lbound -2.94, ubound 2.94 - H1 was accepted