NAV engine giving off too much smoke

[Erick_Cantu]

Perhaps we need to include some default smoke textures in the Content folder of the OpenRails program, and use those if nothing can be found in the GLOBAL folder...

I'd offered the testing versions of my smoke textures to the OR team for that potential future purpose in the same thread where I uploaded the sky and light glow. It could also open up the possibility of having several different particle densities (set by alpha intensity - I had standard, medium, and heavy) and having a default, medium, and heavy density similar to how light glow can be set currently.