Fixed and clarfied comments and math
-Deflections should work now
-Implemented score_delay, which will allow paddle movement but not ball movement for a period after someone scores
-Removed randomized ball position (retaining slope seems like a more elegant way to add variety)
-Paddles don't yet impart simulated momentum on the ball. When this is implemented, there will be a minor and isolated miscalculation if the ball deflects off of moving paddle and then a wall in the same cycle, which should be unlikely (it is literally and figuratively a corner case).
 On branch master
	modified:   hidev/pong.c