Dynamic draw value

Try to avoid repetition draws at early midgame,
this should give an edge against weaker opponents
and reduce draw rate.

Tested for regressions with SPRT[-3, 1] and
passed both short TC
LLR: 2.95 (-2.94,2.94) [-3.00,1.00]
Total: 68498 W: 12928 L: 12891 D: 42679

And long TC
LLR: 2.96 (-2.94,2.94) [-3.00,1.00]
Total: 40212 W: 6386 L: 6295 D: 27531

bench: 7990513
Retire UCI_AnalyseMode option

It has been obsoleted out already some time ago
and currently there is no point in changing eval
score according to if we are in game or analyzing.

So retire the option.

No functional change.
Simplify Bitboards::pretty

No functional change.
Rename xxx_to_char() -> to_char()

No functional change.
Remove limit of minimumSplitDepth

There is no reason why an user cannot set
it at a value less than 4.

No functional change.
Pass CastlingFlag argument only

Instead of Color and CastlingSide. Change functions API
accordingly.

No functional change.
Revert dynamic draw value

When tested with weaker engines did not
performed as expected, actually it was even
a regression from standard version.

bench: 8430785
Some minor cleanup stuff

I came across while browsing the code.

No functional change.
Fix dbg_mean_of() for negative numbers

Type should be int64_t instead of uint64_t

No functional change.
Rename castling flag to castling right

This is a more conventional naming as
reported also in:

http://chessprogramming.wikispaces.com/Castling+rights

No functional change.
Retire SERIALIZE macros

Explicitly write the 'while' loops. This adds some
code but makes clear what's the code behind the
macro.

No functional change.
Simplify generate<EVASIONS>

No speed regression, tested with both perft and
bench.

No functional change.
Simplify pseudo_legal()

Big simplification of pawn move check.

Code has been tested with a brute force approach: for
every position reached during a bench search, the function
has been called for each combinations of Move(from, to)
and verified the result is the same of old code.

Actually this function is very critical becuase is the
one that ensures corrupted TT moves are discarded, so
to properly test it a simple bench is not enough.

Verified also speed is not changed.

No functional chnage.
Print dbg counters after bench

Print last debug counters update just
before to exit benchmark.

Suggested by Stephane Nicolet.

No functional change.
Small simplification in gives_check

Use switch statement also for normal case.

No speed regression.

No functional change.
Use std::count in pos_is_ok()

No functional change.
Merge hash key computation functions

No functional change.
Further merge StateInfo setup functions

No functional change.
Reformat do_castling()

No functional change.
Re-add link time optimization on OS X

In the new version of clang, -O4 does not imply -flto, so we set the
flag