First Hot Rod 2.0 improvements

https://issues.jboss.org/browse/ISPN-3529
* Spec can be found in https://gist.github.com/galderz/9464047

https://issues.jboss.org/browse/ISPN-833
* Remove a long lasting limitation

Documentation has not yet been updated. Once we're happy with the code, I'll resubmit including the documentation.