Convert init of eval to async option

So to be done only once at startup and in the (unlikely)
cases that a relevant UCI parameter is changed, instead
of doing it at the beginning of each search.

No functional change.

Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Simplify undefended pieces to bishop/knight only
Double pinner bonus

Fine tune newly introduced pinner bonus score:

After 34696 games at 2"+0.05
Mod vs Orig 7474 - 7087 - 20135 ELO +3 (+- 2.4)

Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Introduce Eval namespace

Wrap evaluation related stuff and reshuffle
a bit the code.

No functional change.

Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Merge branch 'master' into undefended_pieces
Fix time_to_msec() precision

Result of t.time * 1000 should be a 64 bit value, not an int.

Bug reported by several users.

No functional change.

Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Don't sync with C library I/O buffers

Now we are forced to just use C++ iostream becuase
buffers are independent and using C library functions
like printf() or scanf() could yield to issues.

Speed up of about 1%.

No functional change.

Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Fix UCI 'button' options

When a button fires UCIOption::operator=() is called and from
there the on_change() function. Now it happens that in case of
a button the on_change() function resets option's value to
"false" triggering again UCIOption::operator=() that calls again
on_change() and so on in an endless loop that is experienced
by the user as an application hang.

Rework the button logic to fix the issue and also be more clear
about how button works.

Reported by several people working with Scid and tracked down
to the "Clear Hash" UCI button by Steven Atkinson.

Bug recently introduced by 2ef5b4066e649.

No functional change.

Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Retire "ucinewgame" UCI option

UCI protocol it is not clear about what the engine
should be supposed to do when "ucinewgame" is
received. Stockfish simply sets the position to
start FEN, but it is redundant becuase the GUI always
resends the position after "ucinewgame" command, so
it seems we can safely ignore that command.

No functional change.

Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Don't use "OwnBook" by default

Stick to UCI protocol that says:

* by default all the opening book handling is done by the GUI,
  but there is an option for the engine to use its own book
  ("OwnBook" option, see below)

No functional change.

Signed-off-by: Marco Costalba <mcostalba@gmail.com>
UCI buttons don't need a value

Take advantage of this to further simplify the code.

No functional change.

Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Rename occupied_squares() to pieces()

Also some microoptimizations, were there from ages
but hidden: the renaming suddendly made them visible!

This is a good example of how better naming lets you write
better code. Naming is really a kind of black art!

No functional change.

Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Revert to byTypeBB[0] storing occupied squares

As it was in Glaurung times. Also rearranged order
so that byTypeBB[0] is accessed before byTypeBB[x]
to be more cache friendly. It seems there is even
a small speedup.

No functional change.

Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Merge remote-tracking branch 'upstream/master' into undefended_pieces