Cycles: add Object Info node, with outputs object location, object/material

pass index, and a random number unique to the instance of the object.

This can be useful to give some variation to a single material assigned to
multiple instances, either manually controlled through the object index, based
on the object location, or randomized for each instance. 

http://wiki.blender.org/index.php/Doc:2.6/Manual/Render/Cycles/Nodes/More#Object_Info

intern/cycles/render/nodes.h

@@ -285,6 +285,11 @@ public:
 	SHADER_NODE_CLASS(LightFalloffNode)
 };
 
+class ObjectInfoNode : public ShaderNode {
+public:
+	SHADER_NODE_CLASS(ObjectInfoNode)
+};
+
 class ValueNode : public ShaderNode {
 public:
 	SHADER_NODE_CLASS(ValueNode)