Make model viewer more customizable

[acyc070]

for example: playing speed 0.25, 0.5, 2.0 etc, texture interpolation, customizable lighting (ambient color, diffuse color), smooth shading, fov, etc

[acyc070]

many model viewers from that days has these features, but this viewer doesn't

[ManDude]

You are free to contribute such features.

[acyc070]

I'm not good enough to write this code myself

[acyc070]

progress?