v2.0.0

• stage_dataset has been reimplemented from scratch. The new engine is
  expected to be much faster in most cases.

• __getitem__ on staged datasets used to never cache data when reading from
  unmodified datasets (before the first call to __setitem__ or resize()) and
  used to cache the whole loaded area on modified datasets (where the user had
  previously changed a single point anywhere within the same staged version).

  This has now been changed to always use the libhdf5 cache. As such cache is very
  small by default, users on slow disk backends may observe a slowdown in
  read-update-write use cases that don't overwrite whole chunks, e.g. ds[::2] += 1.
  They should experiment with sizing the libhdf5 cache so that it's larger than the
  work area, e.g.:

  with h5py.File(path, "r+", rdcc_nbytes=2**30, rdcc_nslots=100_000) as f:
      vf = VersionedHDF5File(f)
      with vf.stage_version("r123") as sv:
          sv["some_ds"][::2] += 1

  (this recommendation applies to plain h5py datasets too).

  Note that this change exclusively impacts stage_dataset; current_version,
  get_version_by_name, and get_version_by_timestamp are not impacted and
  continue not to cache anything regardless of libhdf5 cache size.

• Added support for Ellipsis (...) in indexing.