3x3 Pattern indexing implemented in board.
All 3x3 pattern 24-bit indexes (one for each intersection)
are automatically updated inside the board, and it is now
possible to reference the 3x3 pattern of an intersection
by array lookup.

Patterns include the following informations(8x for every pattern):
-Empty (000)
-Border (000)
-Black stone (10x)
-White stone (11x)
-Stone in atari (xx1)

9x9 board overall performance at root decreased from 21kpps
to 18kpps.