Major Overhaul to Hints and Scoring

One of my students said that the Hint should really just show you all possible next moves toward a solution.  I had considered this before, but I didn't realize until that moment that this could be done graphically.  Now, pressing the Hint button generates arrows that show all the moves that lead toward a solution.

Since the Hint has gotten more powerful, I changed some of the behavior around it.  Hints are now a limited resource that must be managed.  You start with no hints available, and you gain one hint for each round you solve without any aids (Undo, Hint, or Give Up).   The number of hints available decreases by 1 each time Hint is used.  

The number of hints is also the bonus earned when solving the puzzle.  A round where you begin with 2 hints that was solved without aids would see the number of hints increase to 3 and then the round would earn 4 points.  Solving the same puzzle but using Undo would see the number of hints remain at 2, and you would earn 3 points.  

If you used Hint one time during that round, the number of hints available would be 1 and the solution would only earn 1 point.  The bonus does not apply if Hint is used even one time during a round.  You can only earn 1 point.  However, the hints you retain will count toward the bonus of a future round.  

When there are no hints available, you can't use Hint, but you can still use Give Up.  (If you had hints available, using Give Up takes them away.)

Please try out this new version!  I think the hint and scoring system is a lot better, and more fun.  

This new version is current with all distributions: Android, Windows, Mac, and both older and newer Linux.