Hide lower half of player ellipsoids

[Akuli]

Simplifies many things. Changes the look and feel of the game.

Todo:

• When standing on top of another player, walls shouldn't affect whether you can move but they apparently do When standing on top of another player, walls shouldn't affect whether you can move but they do #85
• Draw order can be wrong when on top of another player (rotate to see) (its a feature, not a bug)
• Can't jump on top of wall and stay there Can't jump on top of wall and stay there #84
• Make sure can't hit enemy through wall add comment