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. The tests all pass if I create a jar from the commit specified above and include it in my path.

Aside from that everything else is working nicely. It would be awesome to finally have support for Neo4j 2.x in neo4j-scala