GRAILS-6791 - rig up JSON and XML errors marshallers in GrailsUnitTestCase to simply unit testing code that renders validation errors as XML or JSON.
GRAILS-6791 - rig up JSON and XML errors marshallers in GrailsUnitTestCase to simply unit testing code that renders validation errors as XML or JSON.

clockworkorange/grails-core,clockworkorange/grails-core,clockworkorange/grails-core,erdi/grails-core,clockworkorange/grails-core,erdi/grails-core,clockworkorange/grails-core,erdi/grails-core