Changes to ensure backward compatibility with Unit Tests.
Merge branch 'master' of https://github.com/neo4emf/Neo4EMF

Conflict resolution.

Conflicts:
	fr.inria.atlanmod.neo4emf.tests/src/fr/inria/atlanmod/neo4emf/tests/reflection/LoadTest.java
	fr.inria.atlanmod.neo4emf/src/main/java/fr/inria/atlanmod/neo4emf/impl/Neo4emfResource.java
New NESession class, for simplifying things.
Several refactorings and code improvements.