Adds support for specific shadernodes

Blender shader nodes is a complex system to create custom materials.
This commit detects shader nodes configuration for :
- Kerbal Space Program exporter https://github.com/taniwha-qf/io_object_mu
- Cycles baking script https://developer.blender.org/T40265
If one of those configurations is detected, the material is transformed into classic fixed blender pipeline.