message: Remove the internal code offset restriction for consistency with other languages.
  (The concern about unexpected construction is unwarranted.)
diff: /** Internal error code base value. */
  var BASE = 100000;
  - // There is no way to make the constructor private, so only add BASE if the
  - // internal error code is less than BASE, as a safety check. In this way a
  - // MslError could be created directly that is not one of the defined
  - // constants.
  - if (internalCode < BASE){
  - internalCode = BASE + internalCode;
  - }
  -
  // The properties.
  var props = {
  - internalCode: { value: internalCode, writable: false, configurable: false },
  + internalCode: { value: BASE + internalCode, writable: false, configurable: false },
  responseCode: { value: responseCode, writable: false, configurable: false },
  message: { value: msg, writable: false, configurable: false }
  };
  