- Disable VertexPaint and WeightPaint for OB_MATERIAL and OB_RENDER.
Users want to see the final result
- When in OB_SOLID, the active object should be rendered without any
color. The lighting information is multiplied with the
VertexPaint/WeightPaint color
- Removed the use_shading flag from VertexPaint and WeightPaint
- add method to check if render engine should draw without color
(DRW_object_in_only_lighting_mode)