0.6 released

Fix some cases where the html colors decoding was incorrect
The GraphMLNode and GraphMLEdge classes now have both a hashCode and an equals method, and are comparable
Add a nodeSet() method in the GraphMLDiagram to get a set over the nodes
The GraphMLNode, GraphMLEdge, and GraphMLDiagram classes now are clonable
Allow to repatriate a node from a diagram to another one
Integrate the BSD JUNG library in the model. Now the GraphMLDiagram implements the JUNG Graph interface
Add a support JGraphml-layout.jar jar file which allows to apply layout algorithms to a diagram. This jar file uses code from the BSD JUNG library
The distribution now contains 3 jars: the JGraphml.jar jar file contains only the core classes (excluding the layout classes), the JGraphml-layout.jar jar file contains only the layout classes, and depend on collections-generic-4.01.jar file, and the JGraphml-all.jar file contains all the classes for the library
Graphs can now be undirected. Note that in this case all nodes are undirected