message: update error messages in parallel_for
diff: @@ -29,7 +29,7 @@ namespace ospcommon {
  static_assert(has_operator_method_with_integral_param<TASK_T>::value,
  "ospcommon::parallel_for() requires the implementation of "
  "method 'void TASK_T::operator(P taskIndex), where P is of "
  - "type short, int, uint, or size_t.");
  + "type unsigned char, short, int, uint, long, or size_t.");
  parallel_for_impl(nTasks, std::forward<TASK_T>(fcn));
  }
  @@ -42,7 +42,7 @@ namespace ospcommon {
  static_assert(has_operator_method_with_integral_param<TASK_T>::value,
  "ospcommon::serial_for() requires the implementation of "
  "method 'void TASK_T::operator(P taskIndex), where P is of "
  - "type short, int, uint, or size_t.");
  + "type unsigned char, short, int, uint, long, or size_t.");
  for (int taskIndex = 0; taskIndex < nTasks; ++taskIndex) {
  fcn(taskIndex);
  