New physics and scoring system (AI partially broken)

New physics and scoring system (AI partially broken)

Changes from February 2nd, with some clean-ups today.

New physics and scoring system that has more "fault"
possibilities, like hitting the net, multiple bounces
of the ball, etc..

Based on the new physics, a more advanced scoring
system has also been introduced that can handle the
new events that result in a score.

The serving has been fixed - now the serving does not
change for every score, but on a per-game basis.

Smash and topspin are new and can be played by P1
with e (topspin) and f (smash). The physical properties
of these still have to be optimized.

The new changes break the AI, and the AI now is very
dumb again. We need to work on a improved AI that takes
advantages of the new information available via the
physics engine.

Some old, unused variables have been removed.