Arasan 11.0

[jdart]

Arasan 11.0 is available from http://www.arasanchess.org

Changes in Arasan 11.0:
1) Re-work to use "magic" bitboard logic instead of rotated bitboards. About
20-25% speedup from this.
2) Eval re-written to use bitboard attack functions for king saftey, mobility.
3) Some changes and fixes to search (especially LMR).
4) Check extensions are done at ply=0 now.
5) Substantial code cleanup, more consistent variable/function naming,
remove obsolete or redundant code.
6) g++ 3.2 and earlier are no longer supported.
7) Various scoring changes, including fixes to outside passed pawn scoring.
8) Remove unsafe optimization for q-search when in check.
9) Remove lock on main hash table - speeds up multi-threaded searches (thanks
to Bob Hyatt).
10) New position learning system - keeps learn data in a text file vs a
book file. Learn data is loaded into the main hash table (simpler and
avoids locking). Fixes to position learn code.
11) Fixes for loss on time with very short time controls.

This version is also much more stable than 10.4 when run with multiple threads.

Note that the book format has changed, and also the format of the data files (bitbases for KPK). This shouldn't normally be a problem since everything is packaged together (in the zipfile or installer) but don't try to use books from previous versions.