12 bit eval range with 20 bit move

[jhonnold]

Bench: 3680773

This patch does three things:

• Removes all endgame related code. It didn't really do anything anyways.
• Clamps the static eval range to [-2048, 2047] (12 bits)
• Re-scheme the moves to fit into 20 bits. This change had no impact on the engine.

Combining these three patches, I'm able to store the move and static eval in the TT in a singular int32_t, allowing a 10 byte TT entry. This can be used with a 2 byte padding with 3 entries to create a 32 byte bucket, increasing the # of TT entries by 50%.

High Hash Pressure Tests

ELO | 4.88 +- 3.30 (95%)
SPRT | 6.0+0.06s Threads=1 Hash=2MB
LLR | 2.95 (-2.94, 2.94) [0.00, 3.00]
GAMES | N: 20928 W: 5314 L: 5020 D: 10594
http://chess.grantnet.us/test/33940/

ELO | 6.47 +- 3.88 (95%)
SPRT | 30.0+0.30s Threads=1 Hash=8MB
LLR | 2.97 (-2.94, 2.94) [0.00, 3.00]
GAMES | N: 14552 W: 3580 L: 3309 D: 7663
http://chess.grantnet.us/test/33943/

ELO | 10.21 +- 5.11 (95%)
SPRT | 4.0+0.04s Threads=8 Hash=8MB
LLR | 2.96 (-2.94, 2.94) [0.00, 3.00]
GAMES | N: 8650 W: 2241 L: 1987 D: 4422
http://chess.grantnet.us/test/33945/

No-Adjudication Verification

Elo | 1.66 +- 2.82 (95%)
SPRT | 8.0+0.08s Threads=1 Hash=8MB
LLR | 2.94 (-2.25, 2.89) [-2.50, 0.50]
Games | N: 27912 W: 6751 L: 6618 D: 14543
Penta | [106, 3140, 7336, 3263, 111]