Particle system requests.

Presently, messing with PSYS_SRC_OMEGA even slightly forever alters the 'aim' of the particle system, even after resetting the particle system. We need a PSYS_SRC_TARGET_OMEGA or something.

Also, a way to dynamically change color, generation distance, speed, and size of particles would be handy as well, unless it is expected of us to simply jump between seven or eight different particle systems for each variation. Or perhaps just the ability to run multiple particle systems on a single prim.