Arasan 13.3

[jdart]

Arasan 13.3 is available from http://www.arasanchess.org. This is the version that played in the recent ACCA Pam-Am CCC event.

Changes in Arasan 13.3:
1) In Winboard mode, Arasan still accepts but does not rely on the
deprected "white" and "black" commands to keep track of the
computer's side of the game.
2) Winboard "level" command accepts time of form mm:ss and allows decimal
times.
3) More general code for trapped bishop.
4) Static null pruning is implemented.
5) Dynamic null reduction based on score (aka "smooth scaling").
6) Changes to razor & futility margins and related code.
7) Fixes to history pruning. History table is global now, not per-thread.