Create a NodeGraph

[Timmoth]

Instead of having to manage the creation of Nodes manually create a 'Node Graph' which based on the number of parameters given to a Factory Method manages the instantiation and connection of nodes.

E.g
nodeGraph.Add("T1", "U1", "U2", "B1", new TernaryProbabilityChooser(1, 1, 1));
nodeGraph.Add("U1", "T1");
nodeGraph.Add("U2", "T1");
nodeGraph.Add("B1", "T1", "End1", new DeterministicChooser(BinaryChoice.Item1));