hdf5

Merge pull request #543 in HDFFV/hdf5 from ~BYRN/hdf5_adb:hdf5_1_8 to hdf5_1_8

* commit 'c13e0835f70b3ba9d9d706d772b5fa0f2a534cbf':
  Add missing creation order flag set
  Update usage reference file for test
  Remove unavailable argument
  Add missing variable
  HDFFV-8611 preserve creation order for root group