hdf5_msb

Merge pull request #2863 in HDFFV/hdf5 from ~DEROBINS/hdf5_der:develop_minor to develop

* commit '49e01e594eb2d0c25455e7ff71eed3de074fd15b':
  Adds RELEASE.txt note about HDFS VFD stubs being removed
  Removes inappropriate file locking call
  Trivial whitespace change to H5Pencdec.c
  Minor refactoring based on 1.10 normalization work
  Trivialities noticed while normalizing 1.10