add rollout for notes in vrayMat

[andrewjohn81]

With sharing files it is ever important to be able to explain any strange settings that may be there and why they are there.

This applies mostly to materials, but maybe other things as well.

I think it would be nice to have a rollout in the vray materials to be able to add notes.

With the growing site, vray-materials.de, this could be especially helpful.

[RErender]

Easy enough to add a notes rollout to a material with a notes field with script, but vraymat won't hold thm in a library till the next release.

[Dman3d]

yeah that would be handy