ChangeLog
Revising the bpugraph concept
We need a public but very limited ANode and BNode class
It can be used with ItemSetTraits and with some special maps
By example:
DescriptorMap<Graph, ANode>
InvertableMap<Graph, ANode, string>
IterableBoolMap<Graph, ANode>
IterableIntMap<Graph, ANode>
IterableValueMap<Graph, ANode, string>