[REQUEST] Vertex Color Creation / Modification

Having the ability to add and change vertex color would be super helpful for creating more complex materials. Its also a way to store some simple data within the vert's. I am not sure if this exists or not, but I couldn't find any way do this.

A possible solution would be to have a series of nodes to handle vertex color creation and manipulation. Below are several nodes I would suggest.
- Create Vertex Color Layer (layer name)
- Set Vertex Color for selection (color, alpha, blending mode, layer name)
- Get Vertex Color by index (index, layer name) returns a color and alpha
- Delete Vertex Color Layer (layer name) < for clean up

For the blending mode, I would recommend keeping with the brush blending modes currently in blender. I tried to keep my suggestions in line with how vertex painting in blender currently works, so artists would have an easier time with it.