Simplify pawnless endgame evaluation

Retire KmmKm evaluation function. Instead give a very drawish
scale factor when the material advantage is small and not much
material remains.

Retire NoPawnsSF array. Pawnless endgames without a bishop will
now be scored higher. Pawnless endgames with a bishop pair will
be scored lower. The effect of this is hopefully small.

Consistent results both at short TC (fixed games):
ELO: -0.00 +-2.1 (95%) LOS: 50.0%
Total: 40000 W: 7405 L: 7405 D: 25190

And long TC (fixed games):
ELO: 0.77 +-1.9 (95%) LOS: 78.7%
Total: 39690 W: 6179 L: 6091 D: 27420

bench: 7213723
Tweak knight PSQT tables

Passed both short TC:
LLR: 2.97 (-2.94,2.94) [-1.50,4.50]
Total: 31765 W: 6103 L: 5913 D: 19749

And long TC:
LLR: 2.96 (-2.94,2.94) [0.00,6.00]
Total: 38867 W: 6268 L: 5988 D: 26611

bench: 7804908
Increase max hash size to 16GB

TCEC season 3, which is due to start in a few weeks, just
had its server upgraded to 64GB RAM and will therefore allow
16GB hash to be used per engine.

This is almost the upper limit without changing the
type of size and hashMask. After this we need to
move to uint64_t instead of uint32_t.

No functional change.