message: Error handler: Include a couple more properties
  These might help with debugging.
diff: @@ -37,7 +37,11 @@ try {
  'lineno',
  'error',
  'stack',
  - 'enduser_message'
  + 'enduser_message',
  + 'defaultPrevented',
  + 'eventPhase',
  + 'isTrusted',
  + 'returnValue'
  ])
  );
  