Hornetq 756

I was investigating https://issues.jboss.org/browse/HORNETQ-756 and it seems that this is already resolved.

I suspect that this was some old behaviour of Rest Easy as I could not see anything in the history of QueueDestinationsResource that had changed to set the content type.

This pull request contains two new tests for creating a queue and topic that checks for a 415 if the content type does not match. These tests are probably unnecessary as it is really testing the behaviour of Rest Easy.