Some new particle FX requests

[Argh]

1. I'd like to be able to define custom directories to use the Smoke animation. Same number of frames, etc., just with a custom directory. Then we could have custom Smoke that was animated, with different colors, etc.

2. Could somebody make a version of SimpleParticleGenerator that could use such directories? That'd be even cooler (although, to be admitted, not suitable for most things due to lag).

3. I'd like an animated version of HeatCloud.

4. I'd like to be able to redefine the animations for the default Burning Trees, smoke from dead units, etc., with custom animations. Those things should all just be made standard particle generators and put outside Spring's core sourcecode, imho.