There was a problem with the
distcheck testing since the test input files
are in ${src_dir} and the test is in ${build_dir}.
So modify run_chunk_hdf4 to copy as necessary.
It turns out that HDF4 supports chunking
(and compression). However the existing
HDF4 code does not support it.
So add HDF4 support for chunking.
Also add a test case.