Improve touch-events for mobile (add guide lines)

[artasparks]

There's a couple things that are related.

1. The action should be moved to touch-end.
2. We should consider adding guidelines. This is a pretty common feature on mobile apps.

I think this would be a great feature. Adding guide-lines for mobile would make it much easier to avoid misclicks

How it would be implemented: touchstart: add guidelines on stone grid touchend: remove guidelines, perform action.