hdf5_ep

Merge pull request #1101 in HDFFV/hdf5 from ~DEROBINS/hdf5_der:vi_develop_normalize to develop

* commit '18fbdebb977d7a4dbaa99ec6b153a49e3b4883d5':
  Cleaned up H5Fmount/unmount code.
  Normalization with vol_integration branch.
  Normalization with the vol_integration branch.