h4h5tools

When netCDF-4 output is enabled, create HDF5 attributes as SIMPLE space even though it has only one element.

By default, h4toh5 creates an HDF5 attribute as SCALAR space if there is only element. If that attribute is of numeric type, netCDF-4 rejects it because it always assumes SIMPLE space for numeric type. Previously, this is handled for attributes in Vdata or SDS. After this fix, the same handling is performed for Image or Vgroup.