Thank you for trusting me, Álvaro!

The current v4 code with Embree in my development code is way too messy. It is more a proof of concept than code good enough to be published, and that's why I have not yet uploaded it to the repository.
I'm now in the process of "deconstructing" my code and rebuilding it with better abstraction/encapsulation foundations. Hopefully it will also be more "correct", have a better style and be easier to maintain and more flexible.
What I'm trying to introduce now in the code are abstractions for a new class I've called accelKernel_t. I will initially create a subclass called embreeKernel_t which will contain the interface to convert internal YafaRay objects into Embree scenes/objects, Embree instances and ray intersections.
For now I will not use the acceleration kernels for anything related to interpolation, materials, shaders, etc. Only to do ray intersections and obtain the ray tmax (therefore the hit point), the object ID, primitive ID of the intersection and the "barycentric u,v". YafaRay will process those using "normal" code to get the interpolated textures, materials, vertex interpolation, etc.
This way, in the future new accelKernel_t derived classes could be added with other kernels (perhaps even GPU based) for such intersection calculations.
I hope to be able to reduce any data duplication and transfer to the minimum possible, but if needed I will sacrifice it to favour abstraction. I think it's worth it
