minor cleanup of neo4j test bootstrapping
#17 changed property order of CdoUnit
#17 aligned instance listeners with bean validation (i.e. required properties may be set in @PreUpdate methods)
#73 added test case for qualified relations
#17 added test for aggregating life cycle methods
#73 added support for qualified one to one relations
#73 added support for qualified x to many relations
#59 make value of @Relation optional