I hope this isn't bike-shedding. I'm working on a Voronoi texture enhancement
(that won't make the 2.80 release window) I am breaking off whatever self
contained changes I hope may be usefull in hopes for inclusion.

The point of this change is to make the abreviation "SVM" for "Shader
Virtual-Machine" easier to find. I also added explanations for a few other
terms here and there too. I hope to be submitting more substantive changes
soon.