Generate discovered checks in qsearch.
Go back to standard futility + SEE pruning in qsearch.
Changes to qsearch pruning. Prune some non-capture evasions.
update test results
Remove redundant trace statement. Fix ASSERT location in qsearch.
Add singleBitSet function to Bitboard class. Use this to avoid
call to popcnt in case no native popcnt exists.
Re-introduce small bonus for minor on outpost square that is not defended
by pawn.
Merge in changes to qsearch + some performance fixes.