Registration of information about classes' position at a taxonomy

[pedropaulofb]

While a first implementation of the Tester captures a single file with all classes that have taxonomic relations (generalization/specialization), the newest version is going to create files for individual taxonomies that exist in each of the catalog's datasets. Hence, the "reachable nodes" field that is available in the dataset csv file makes no sense anymore and must be substituted by fields indicating the node position at the taxonomy, like:

• distance to the closest root node
• distance to the farthest root node
• distance to the closest leaf node
• distance to the farthest leaf node