Code refactor: add separate RGB to BW node and rename some sockets.

intern/cycles/kernel/shaders/node_math.osl

@@ -50,7 +50,7 @@ float safe_log(float a, float b)
 
 shader node_math(
 	string type = "Add",
-	int Clamp = 0,
+	int use_clamp = 0,
 	float Value1 = 0.0,
 	float Value2 = 0.0,
 	output float Value = 0.0)
@@ -96,7 +96,7 @@ shader node_math(
 	else if (type == "Absolute")
 		Value = fabs(Value1);
 
-	if (Clamp)
+	if (use_clamp)
 		Value = clamp(Value, 0.0, 1.0);
 }