message: When creating datasets, convert types to C repr
diff: @@ -336,7 +336,8 @@ impl<T: H5Type> DatasetBuilder<T> {
  fn finalize<D: Dimension>(&self, name: Option<&str>, shape: D) -> Result<Dataset> {
  h5lock!({
  - let datatype = Datatype::from_type::<T>()?;
  + let type_descriptor = <T as H5Type>::type_descriptor().to_c_repr();
  + let datatype = Datatype::from_descriptor(&type_descriptor)?;
  let parent = try_ref_clone!(self.parent);
  let dataspace = Dataspace::try_new(&shape, self.resizable)?;
  