#10 All Edges are directed instead of bi-directional

[rmiesen]

Creating a "bi-directional" edge in Graph# in fact creates directed edges.

Method to reproduce:

1. Create a four-vertex cyclic graph by connecting v1 to v2, v3 to v2, v1 to v4, and v3 to v4.
2. Apply the Eularian Trail algorithm to the graph.

Result: Nothing in the graph is selected, even though the graph, if it were being evaluated in a bi-directional manner, would be Eular.