Ground decals wishlist

1. Ability to reference the ground scar textures (one or many) from weapondefs
2. Control minmax alpha and alpha decay (determines how long the texture decays) from weapondefs
3. Control the grade of glow (maybe how long such glow should stay).
4. Add support for glow colormaps
5. Add a parameter controlling the color elimination determined by dot product of normal and projection vector.
6. Check if LOS shading is something worth doing.
7. Allow forced direction of scar projection (in weapondefs)

Start by locating the ground-scar or ground-decal rendering code and the weapondefs definitions. Review how scar textures, alpha decay, glow, projection direction, and normal-dot color elimination are currently handled. Done would require agreeing on the scope of the seven wishlist items and verifying each supported weapondef control in the engine.

Written by the indexing model from the issue text.