Cycles / Toon BSDF:

* Added a toon bsdf node to Cycles. This was already available as OSL only closure, but is now available inside the SVM backed as well, for CPU and GPU rendering. 
* There are 2 variations available, diffuse and glossy toon, selectable via a menu inside the node. 

Documentation:
http://wiki.blender.org/index.php/Doc:2.6/Manual/Render/Cycles/Nodes/Shaders#Toon

Example render & blend file:
http://www.pasteall.org/pic/show.php?id=51970
http://www.pasteall.org/blend/21579

source/blender/gpu/shaders/gpu_shader_material.glsl

@@ -2063,6 +2063,11 @@ void node_bsdf_glass(vec4 color, float roughness, float ior, vec3 N, out vec4 re
 	node_bsdf_diffuse(color, 0.0, N, result);
 }
 
+void node_bsdf_toon(vec4 color, float size, float smooth, vec3 N, out vec4 result)
+{
+	node_bsdf_diffuse(color, 0.0, N, result);
+}
+
 void node_bsdf_translucent(vec4 color, vec3 N, out vec4 result)
 {
 	node_bsdf_diffuse(color, 0.0, N, result);