Elongated playfields, fixed rotation bug

- Modified checkOverlap to return a collision immediately if a piece has a true element assigned beyond the top of the ledArray, to address a runtime error that could occur when player 1 rotated an "I" piece adjacent to the top border.
- Also modified checkOverlap to return a collision if a piece has a true element beyond the left or right edges of ledArray, so that the leftmost and rightmost borders could be set to zero (elongating the playfields to a more standard size at a small cost to efficiency.)
- Some minor refactoring was done elsewhere.