Changes in Arasan 17.3 (Aug. 2014):
1) Reduce doubled pawn score in endgame.
2) Fix some bugs involving hash size settings for UCI.
3) Minor changes to outpost scores.
4) Fix a couple bugs in "makebook" programs.
5) Some king safety enhancements.
6) Tuning of futility pruning parameters.
7) History pruning disabled.
Fixes to history and killer move handling.
9) Simplify capture extension code and disable "easy nove" if
capturing the last piece.
10) Increase see pruning depth to 1.5 ply.
Changes in Arasan 17.2 (May 2014):
1) Fix "st" command in Winboard protocol to interpret time as seconds
2) Scoring changes: king safety, king cover, weak pawns
Changes in Arasan 17.1 (May 2014):
1) Scoring changes: connected passer code, knight and bishop
piece square tables, new king safety scoring.
2) Add special-case eval code for K vs K+R and K vs K+Q endgames.
3) Bug fix: validate hash move in q-search before using it.
4) Changes to handling of book selectivity option.
5) Adjust variable strength option so bottom end of strength scale
is lower (will blunder sometimes).
6) Increase ply depth in reduced strength mode for very low material
endgames (engine was having difficulty mating in these cases
even at moderate strength settings). This also fixes some
problems with playing into stalemate.
7) Better handling of out-of-memory errors when allocating hashtable.
GUI fix: initialize all engine options at start of game. Fixes
problem with resignation setting not being obeyed.
9) GUI fix: clear any previous game result and other details after
loading a position file.