h4h5tools

Print appropriate error messages when a fake dimension cannot be created.

When -nc4fakedim is specified, dimensions attached to each non-HDF-EOS2 field are also converted. (Those dimensions are called fake dimensions, and the option name may need to be revised.) Those fake dimensions are needed only when a file is hybrid.

A non-HDF-EOS2 field and a non-HDF-EOS2 dimension can have the same name because HDF4 allows this. This is not allowed in HDF5, and it's not straightforward to twist the structure to allow the name conflict. This changelist just prints a proper error message that clearly shows what the problem is.