Tweaking parameters for debugging

Temporarily removed sound and tennisballs to try and make the regular
balls work as well as can be.
Fixed collisions again

There was one lingering bug with colissions that seemingly hs been fixed
where the balls would occasionally change place. I THINK I have fixed it
now, it was due to only one ball being moved in the pre colission step.
Also cleaned up the code with placing options in gameScreen and some
ther small fixes. Currently has a fair amount of ugly debugging code
that I want to remove but we will handle that soon.
Fixed clicking responsiveness and change clickForce

Created a click method on the ball class. Made sure that clicking cannot
occur too rapidly. Added a positive (upwards) vertical component to all
clicks.