nqueens old refactor fixes: scoreRules need to check if row != null + docs nqueens y to rowIndex refactor
use assertUndoMoveIsUncorrupted() in DefaultGreedyDecider (DRY)
rename properties assert*IsUncorrupted to either assert*FromScratch or assertExpected*
EnvironmentMode.NON_INTRUSIVE_FULL_ASSERT to flush out Phreak bugs