Established skeleton code

Added a few functions to:
 1. Store and access historical position data
 2. Use that data to calculate velocity
 3. Determine the direction of movement of the other paddle

Next step is to create functions to:
 1. Determine where the ball will intersect the game field (assuming collision with top/bottom of field)
 2. Determine the direction of ricochet (assuming collision with top/bottom of field)
 3. Determine where the ball will intersect the paddle (based on #2)
 4. Determine direction of bounce with paddle (based on #3)

And thus select the optimal location to move the paddle to, to increase odds of contact.