Blender Git Loki

Removed the experimental (and commented-out) code for FOR and WHILE loops in nodes. This was a feature i tested a while back but was only partially supported by Blender Internal renderer and the old compositor. The main idea was to have nodes that automatically mirror input and output sockets to support incremental changes of "internal variables".

It is not a well-supported feature of the primary node systems (shader, compositor, texture) in Blender. If anybody wants to create a node system that has actual use for loops, they can do so much more elegantly with Python nodes, but it does not have to be a core node type in Blender. Removing this should ease node code maintenance a bit.