Neo4j 2.x compatibility

I've updated Neo4j to version 2.1.3 and added support for nodes with labels.

It's worth noting that there are some issues with the tests in `TypedTraverserRESTSpec` which are related to some problems with the Neo4j `java-rest-binding` raising `IllegalAccessError`. This seems to be fixed with the latest commit e7876af31627fd5c4dc218ac86fd082841edc097 in the `2.0-labels-and-indexes` branch of the java-rest-binding. I've opened an issue at https://github.com/neo4j-contrib/java-rest-binding/issues/72 to get a release but have not heard back.

Aside from that everything else is working nicely. It would be awesome to finally have support for Neo4j 2.x in neo4j-scala