Add SceneObject.Batchable, for situations where dynamic attributes affect rendering
Delete unused shit from lightinglib
Add SceneSunLight.SkyColor for ambient light color outside of light probes
Compute ambient light spherical harmonics when there's no sunlight using scene camera ambient color (this allows cubemaps to show up without sunlight)
Add SceneCubemap, allows cubemaps to be applied in scene worlds
Add a default cubemap texture
Add cubemaps to menu scenes so metallics have a bit of reflection