Added Daniel's Bayes Net code. Converted example code to unit tests. Minor code clean-up.

src/dkohl/bayes/probability/distribution/tree/ProbabilityLeaf.java

@@ -0,0 +1,29 @@
+package dkohl.bayes.probability.distribution.tree;
+
+import java.util.LinkedList;
+
+import dkohl.bayes.probability.Assignment;
+import dkohl.bayes.probability.Probability;
+import dkohl.bayes.probability.distribution.ProbabilityDistribution;
+
+/**
+ * Just a dummy node. Always returns the probability value, ignoring the
+ * assignment.
+ * 
+ * @author Daniel Kohlsdorf
+ */
+public class ProbabilityLeaf implements ProbabilityDistribution {
+
+	private Probability probability;
+
+	public ProbabilityLeaf(Probability probability) {
+		super();
+		this.probability = probability;
+	}
+
+	@Override
+	public Probability eval(LinkedList<Assignment> assignment) {
+		return probability;
+	}
+
+}