integration :  bug #4361 :  Now the existence of axis values are checked before saving a position on the PdC for a predefined classification; the JPA implementation by hibernate doesn't seem to respect correctly the JPA specification with the 'persist' cascading (with the persist cascading in a relationship, the related entities are saved only if they don't exist. Here Hibernate want absolutly create them whatever they already exist or not)
Bug #4361 :  Fix the bug about the position duplication within a single classification. The fix concerns both the javascript front-end of the classification on the PdC and in the JPA entities implied in the definition of a predefined classification on the PdC. For latter, a bean validation constraint (UniquePositions) is added but Hibernate 3.6.10 (or Spring-data) has some bugs in the validation of constraints when saving an entity.

Conflicts:
	ejb-core/pdc/src/main/java/com/silverpeas/pdc/service/DefaultPdcClassificationService.java