Raise max Hash to 1TB
And use size_t where appropriate, as suggested on FishCooking.

No functional change.
Use compiler intrinsic instead of assembly for popcnt
No functional change.
Revert "Use compiler intrinsic instead of assembly for popcnt"

This reverts commit a69f1d7c2060dc7b320a7b4801105df00b22a96a.
Use compiler intrinsic instead of assembly for popcnt
This time, do not break compatibility with some AMD machines that have SSE3 and popcnt, but do
not have SSE4.2.

No functional change.
size_t cast in TranspositionTable::first_entry()
32-bit truncation would make this function bogus when clusterCount >= 2^33 (ie. Hash >= 256 GB).

No function change.
Tune trapped rook penalty

Passed STC
LLR: 2.96 (-2.94,2.94) [-1.50,4.50]
Total: 15687 W: 3352 L: 3199 D: 9136

and LTC (parameter tweaks)
LLR: 2.95 (-2.94,2.94) [0.00,4.00]
Total: 27983 W: 5046 L: 4797 D: 18140

bench: 8330705
Avoid 'double assigments' tricks

Bitboard init code is already noteasy to follow,
so don't make it even harder using 'smart' code.

Also reindent a while loop in standard way.

No functional change.
Retire FakeSplit

    - Currently broken
    - Never been really useful
    - Does not work well with new splitting model

Verified for no regression at STC with 3 threads:
LLR: 2.96 (-2.94,2.94) [-6.00,0.00]
Total: 81905 W: 12122 L: 12381 D: 57402

No functional change
Remove useless condition

Small simplification, suggested by Uri Blass.

passed STC:
LLR: 2.96 (-2.94,2.94) [-3.00,1.00]
Total: 25839 W: 4464 L: 4351 D: 17024

and LTC:
LLR: 2.96 (-2.94,2.94) [-3.00,1.00]
Total: 220039 W: 29981 L: 30131 D: 159927

No functional change.
Small reformat to Skill class

Steamline a bit the implementation of
skill levels. As a side effect we can
retire MultiPV global and use a local
variable instead.

No functional change.
Bonus passed pawn blocked by our pieces

passed STC:
LLR: 2.95 (-2.94,2.94) [-1.50,4.50]
Total: 63965 W: 10950 L: 10692 D: 42323

and LTC:
LLR: 2.95 (-2.94,2.94) [0.00,6.00]
Total: 19237 W: 2740 L: 2562 D: 13935

bench: 7477963
Contempt = 20
Also raise the admissible bounds to (-100,100), as there is no reason to prevent users from using high
values if they want to.

Does not regress in self play:
ELO: 0.10 +-2.0 (95%) LOS: 53.7%
Total: 40000 W: 7084 L: 7073 D: 25843

master vs SF 3
ELO: 182.86 +-2.7 (95%) LOS: 100.0%
Total: 40000 W: 21843 L: 2541 D: 15616

Contempt = 20 vs SF 3
ELO: 189.25 +-2.8 (95%) LOS: 100.0%
Total: 40000 W: 22721 L: 2859 D: 14420

Diff is therefore 6.4 +/- 3.9 elo against a 180-190 elo weaker engine, which is significantly positive,
as expected. This elo difference is likely understated, because of FishTest aggressive draw adjudication
though.

We could push Contempt further, but after 20cp, it would get in the way of FishTest draw adjudication
rule, and is likely to reduce the testing throughput as a result.

bench 8198667
Simplify evaluate_passed_pawns

From a suggestion by David Zar.

No functional change.
Revert Contempt = 20

Despite being neutral at STC, it turned out to be regressive at LTC:

40k games at LTC with Hash=8
ELO: -2.06 +-1.9 (95%) LOS: 1.4%
Total: 39720 W: 5740 L: 5976 D: 28004

40k games at LTC with Hash=128
ELO: -2.69 +-1.9 (95%) LOS: 0.2%
Total: 39149 W: 5702 L: 6005 D: 27442

bench 7477963
Outpost tuning
double mg bonus and half eg bonus.

STC:
LLR: 2.95 (-2.94,2.94) [-1.50,4.50]
Total: 18142 W: 3094 L: 2948 D: 12100

LTC:
LLR: 2.95 (-2.94,2.94) [0.00,4.00]
Total: 83561 W: 11706 L: 11329 D: 60526

bench 7831429