Renamed getMoves() into getChildren(), now it returns a Vector of CheckerBoards that result from moves on the original.
New method jump() will return a vector of just the new boards that result from any possible jumping moves given the current square
Redesigned the adjacency matrix: now each position has four entries, so we can use for instead of while loops,
and also we can use only one matrix instead of two for kings and non-kings. First  number stands for upper-left of the current
square, and each successive number the next adjacent square clockwise.  -1's mean no adjacent square there.  This will also help
because to know where to jump you need to know what direct you're jumping from