Include file attacks in 'major on pawn'

Passed both short TC:
LLR: 2.97 (-2.94,2.94)
Total: 57846 W: 12248 L: 11974 D: 33624

And long one:
LLR: 2.95 (-2.94,2.94)
Total: 9181 W: 1732 L: 1581 D: 5868

bench: 4609948
Micro-optimize perft

Avoid to call perft function when we just need to count
moves, at leaf nodes.

Speed up of almost 2%

No functional change.
Name functions along corresponding UCI commands

No functional change.
Simplify hidden_checkers()

De-templetize and pass color as function argument.
No speed change.

No functional change.
Retire ThisAndAdjacentFilesBB[]

It is unused. Also renamed attack_span_mask to
pawn_attack_span

No functional change.
Retire in_front_bb(Color c, Square s) overload

Explciitly call rank_of() in the few places where
it is used.

No functional change.
Don't explicitize enum values when not needed

Compiler will chose the correct values in sequential
order for you.

Also move file and rank bitboards definitions to
bitboard.h

No functional change.
Move SquareDistance[] to bitboard.cpp

No functional change.
Fix some stale comments

No functional change.
Use calloc() in TranspositionTable::set_size()

Function calloc() already initializes memory to
zero, so avoid calling clear() afterwards.

Also some renaming while there (inspired by DiscoCheck).

No functional change.
Simplify aspiration window loop

Don't open the window in case we find a mate score: this
will be takes care with next patch.

No functional change.
Center aspiration window on last returned score

bench: 4428212
Reorder conditions according to their frequency

This should minimize useless tests.

No functional change.
Simplify search results update

Also some rename while there.

No functional change.
Fix a stale comment

No functional change.
Merge branch 'master' into aspiration
Increase earlier aspiration window size

bench: 4377851
Entering a pawn endgame is no more dangerous

A simplification of the 'dangerous' definition.

Seems neutral at reverse test at long TC

master vs patch
LLR: -2.96 (-2.94,2.94)
Total: 16974 W: 3122 L: 3139 D: 10713

bench: 4689029
Revert "Increase earlier aspiration window size"

This reverts commit b88bc7b7667fc6ddbfc7412fb2c0bfc13e3bf11c.
Merge branch 'master' into aspiration

bench: 4507288