First functioning pass at connectivity.

- added unittests (passing)
    - updated run script to take int for number of subds

bin/iterate.py

@@ -11,6 +11,7 @@ if __name__ == '__main__':
             '(first argument) and dump json to stdout')
     parser.add_argument('type', choices=('cc', 'butterfly'))
     parser.add_argument('mesh')
+    parser.add_argument('refines', type=int)
     opt = parser.parse_args()
 
     cube = json.load(open(opt.mesh, 'r'))
@@ -21,5 +22,6 @@ if __name__ == '__main__':
     else:
         refine = butterfly.refine
 
-    q = refine(p)
-    print(q)
+    for i in range(opt.refines):
+        p = refine(p)
+    print(p)