Refactoring

- changed to maven
- modified hashMap and HashSet to Tree
- modified files path

src/main/java/berack96/lib/graph/ObjectsComparator.java

@@ -0,0 +1,18 @@
+package berack96.lib.graph;
+import java.util.Comparator;
+
+/**
+ * Compare two arbitrary objects.<br>
+ * It uses the method hashCode that every object has to compare two objects.<br>
+ * This is a simple use 
+ */
+public class ObjectsComparator implements Comparator<Object> {
+    static public final ObjectsComparator instance = new ObjectsComparator();
+    
+    private ObjectsComparator(){};
+
+    @Override
+    public int compare(Object o1, Object o2) {
+        return o1.hashCode() - o2.hashCode();
+    }
+}