Changes

Perft can receive another speed boost by [[Hash Table|hashing]] node counts, with a small chance for inaccurate results. Sometimes this is used as a sanity check to make sure the hash table and keys are working correctly. Below is output of [[Stockfish]] for Perft 5: <pre>go perft 5a2a3: 181046b2b3: 215255c2c3: 222861d2d3: 328511e2e3: 402988f2f3: 178889g2g3: 217210h2h3: 181044a2a4: 217832b2b4: 216145c2c4: 240082d2d4: 361790e2e4: 405385f2f4: 198473g2g4: 214048h2h4: 218829b1a3: 198572b1c3: 234656g1f3: 233491g1h3: 198502 Nodes searched: 4865609</pre>