Stubbed out subd.butterfly and added testing script

bin/iterate.py

@@ -0,0 +1,24 @@
+import argparse
+import json
+
+from surf.geometry import PolygonMesh
+from surf.subd import cc
+from surf.subd import butterfly
+
+
+if __name__ == '__main__':
+    parser = argparse.ArgumentParser(description='Prune orphan PCDs from couchdb')
+    parser.add_argument('type', choices=('cc', 'butterfly'))
+    parser.add_argument('mesh')
+    opt = parser.parse_args()
+
+    cube = json.load(open(opt.mesh, 'r'))
+    p = PolygonMesh(**cube)
+
+    if opt.type == 'cc':
+        refine = cc.refine
+    else:
+        refine = butterfly.refine
+
+    q = refine(p)
+    print(q)