This is the port of the large opening book for crafty.

It was created with "book create book.txt 60 3" (see the crafty
documentation and online help for a more thorough explanation of what
this does) which discards all openings not played in at least three
games which I expect to be a reasonable constant, but I am open to
suggestions on this.

- Stefan Eggers <seggers@semyam.dinoco.de>
