use an array for board points but link points of the same color in a list
implement Board.visitChain
replace ChainPointCollector with Board.visitChain
progress toward making PrisonerFinder more efficient and getting rid of LibertyFinder
more progress toward getting rid of LibertyFinder, drop atari detection
visit diagonals only if the point has no neighboring liberties
quit using ArrayShortList in Board class
use pre-allocated arrays for tracking visited chain points
declare a few simple methods as final in case the JIT is able to inline them
finish getting rid of commons-primitives lib