Tutte Code Version 0.9.15
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The following updates have been made:

* Incorporated the vorder push heuristic suggested by Michael Monagan.
  As part of this, I've added the ability to sort the vertex order
  according to a depth-first or breadth-first search.  Again, this was
  suggested by Michael and it really makes a big difference for
  computing Truncated Icosahedron (and probably lots of other graphs).
  I've got to do some more experimentation!