Huge speed up

Huge speed up and relaxed check on piece disambiguation rule, now we allow a disambiguation rule even if not strictly needed.

Build Polyglot book

Build a Polyglot book out of a PGN file.

This tool shared teh Makefile of Stockfish, so compilation steps are the same, for instance like:

make build ARCH=x86-64-modern

Binary name is parse (or parse.exe under Windows), you run it as:

./parse myfile.pgn

And it will create a myfile.bin that is the Polyglot book out of the PGN.

Tool is relatively forgivin in the input moves in SAN format, but requires:

• A correct disambiguation of moves like Rac3, in particular if only one move is legal then no disambiguation
• Castling should be O-O, not 0-0 (big O, not zero)