remove dependency on PropertyContainer

 * Created a new interface called DetachedPropertyContainer that is similar to PropertyContainer but decouples from the neo4j embedded database (e.g. no GraphDatabaseService). #1
 * Fixed a test case that depended on the order of a Set.
completely removed neo4j-kernel dependency #1
Merge pull request #2 from pdtyreus/feature/remove_property_container

Remove dependency on neo4j-kernel