Mutable Materials

[bjornbytes]

Adds support for modifying materials after they're created.

• Material:get/setNumber
• Material:get/setVector
• Material:get/setTexture

I'd like to find a way to avoid verbosely converting between MaterialInfo/MaterialData if possible.

Other things to consider:

• Material:clone?
• Deprecate Material:getProperties?
• newMaterial(texture)?
• Material:setTexture(texture) defaults to color?
• Explicit Material:get/setColor methods that do sRGB conversion, or just always do sRGB conversion for color/glow vectors?
  • Former would work with custom material properties better.
  • Material:setColor('color', r, g, b, a) is awkward, but could do the same treatment as Material:setTexture(t). Maybe rename color to baseColor?
  • Material:setColor could also accept a hexcode, which would be nice.