Cleanup a few conditioning nodes.

node_helpers.py

@@ -0,0 +1,10 @@
+
+def conditioning_set_values(conditioning, values={}):
+    c = []
+    for t in conditioning:
+        n = [t[0], t[1].copy()]
+        for k in values:
+            n[1][k] = values[k]
+        c.append(n)
+
+    return c