[Feature Request] Merge Toon Shading

Please merge the Toon Shading branch:

https://github.com/marynate/UnrealEngine/tree/4.12-toon

as requested by the users here:

That is so, so needed for anything non-realistic, and looks not that hard to do from a glance at the code… small modifications in ~20 files… pretty, pretty please?

For now, I’ll try to build the engine and merge the changes myself, but this is quite a barrier to entry and trying to stay up to date with future versions sounds… cumbersome. And that work should not be done everytime by everyone who needs this.