hdf5_ep

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

* commit 'bf570b1a7ca3b9cbd4a59f0933a19ce1bcc99103': (71 commits)
  Amend tests to explicitly use H5Dcreate2 and H5Dopen2
  Revert malloc's back to using hard-coded type for sizeof
  Minor comment refactoring
  Update documentation
  Finish up Parallel Compression test scaling work
  Partial update for scaling parallel filters tests
  Modify t_dset.c in lieu of Parallel Compression changes
  Updated H5C__flush_single_entry() in H5C.c to correct duplicate metadata write bug observed in 1.10.1.
  Amend MANIFEST
  Add test for write parallel; read serial case
  Fix uninitialized array issue in test
  Test updates
  Fix bug where incorrect amount of data was being read from the file
  Add data verification for first half of tests
  Start adding data verification
  Switch tests over to use testing macros
  Updates to parallel filters tests
  Move test files to testpar directory
  Add test file to build process
  Suggested changes from code review
  ...