Cycles: change Ambient Occlusion shader to output colors.

This means the shader can now be used for procedural texturing. New
settings on the node are Samples, Inside, Local Only and Distance.

Original patch by Lukas with further changes by Brecht.

Differential Revision: https://developer.blender.org/D3479

release/scripts/startup/nodeitems_builtins.py

@@ -208,6 +208,7 @@ shader_node_categories = [
         NodeItem("ShaderNodeNewGeometry"),
         NodeItem("ShaderNodeWireframe"),
         NodeItem("ShaderNodeBevel"),
+        NodeItem("ShaderNodeAmbientOcclusion"),
         NodeItem("ShaderNodeObjectInfo"),
         NodeItem("ShaderNodeHairInfo"),
         NodeItem("ShaderNodeParticleInfo"),
@@ -240,7 +241,6 @@ shader_node_categories = [
         NodeItem("ShaderNodeEmission", poll=object_shader_nodes_poll),
         NodeItem("ShaderNodeBsdfHair", poll=object_shader_nodes_poll),
         NodeItem("ShaderNodeBackground", poll=world_shader_nodes_poll),
-        NodeItem("ShaderNodeAmbientOcclusion", poll=object_shader_nodes_poll),
         NodeItem("ShaderNodeHoldout", poll=object_shader_nodes_poll),
         NodeItem("ShaderNodeVolumeAbsorption"),
         NodeItem("ShaderNodeVolumeScatter"),