hdf5_der

* Added a test that fails on overwriting a chunk with H5DOwrite_chunk().
  The overwrite line is currently commented out so the tests pass.
* Changed the test_dset_opt.c file name from test_dectris.h5 to
  test_dset_opt.c and updated the autotools and CMake.
* Updated the test_dset_opt.c file to use both old and new file
  formats when testing.