Created PowerBall..

This will be used as a power up for the player. PowerBar activates this.
Multiple adjustments for PowerBall implementation..

The overridden halfsize in PlayerBall is now in Ball.
GDComp has some changes with the halfsize it gets from circles in collision handling.
Implemented PowerBall in the collision handling for Wall, ScoreBall and PlayerBall.
PowerBar now creates the PowerBall in UsePower.
PowerBar now drops with 50 per second (up from 20).
PowerBar now gains 2.5 per friendly without multiplier (up from 1).