Vehicle physics with ammo

[vincentfretin]

I started using ammo vehicle physics in aframe directly from https://github.com/kripken/ammo.js but not using aframe-physics-system
in this experiment https://github.com/c-frame/aframe-racing-game
I didn't think yet how to use it with an existing scene with aframe-physics-system ammo. For now I just did a simple conversion in an aframe component of the kripken's demo. If someone have any thought about it, they can contribute to the discussion.

FYI the MozillaReality ammo build we use in the examples in aframe-physics-system doesn't have vehicle physics. You need the latest build from kripken's repo https://cdn.jsdelivr.net/gh/kripken/ammo.js@8f8b7187ef74994093318645e5e96b11d982688a/builds/ammo.wasm.js
I have no idea if there is incompatibilities or not using the latest build with aframe-physics-system.