Change == null to StringUtils.isEmpty
Don't cause resteasy to hang when the exception from a service call is thrown by a server method (that is, when a server makes a call to a remote service, any exception thrown by the JAX-RS client for that service shouldn't cause this service error renderer to choke)
Fix how remote rich exceptions are converted into RestFailures, using a ClientResponseFilter for the JAX-RS 2.0 client