hdf5

Merge pull request #1970 in HDFFV/hdf5 from ~BYRN/hdf5_adb:hdf5_1_12 to hdf5_1_12

* commit 'cc6537dc66555a0f37b687ae8eb32a21ab1fd41d':
  HDFFV-10919 merge synching
  HDFFV-10408,10918 add note
  Whitespace and macro semi-colon
  Whitespace synch
  HDFFV-10918 add tests for h5repack ext storage