hdf5_ep

Merging in latest from upstream (HDFFV/hdf5:refs/heads/develop)

* commit 'edcba1ce2e11f80d20fcce8f4cfacae1308bf839':
  more cleanup
  Max Library "index" should be 7.
  not use hdf5 private header
  fix float type cmp warning
  fix float type cmp warning
  fix missing prototype warning
  fix uninitizlized warning
  change it back
  pick up missing piece
  fix unused related warnings
  removed unused parameter
  more fix and address comments
  remove unsed var,function,macro, etc