Also:
- add back call to `include_directories` for PnetCDF
- ensure `MPI` is found for PnetCDF with serial HDF5

* main:
  Escape a character causing a doxygen error.
  Updated release notes.
  Added a comment block for future reference.
  more syntax fixes
  Update CMakeLists.txt
  CMake: Find HDF5 header we can safely include for other checks
  moving functions and macros to new file, lowercase things
  Update release notes.
  lowercase
  lower case
  lowercase
  moving functions and macros to a file
  CMake: Add support for UNITY_BUILD
  Change signature of `nczm_sortenvv` to take `size_t`
  Try to more consistently use `size_t` for argument of `nclistlength`
  Try to more consistently use `size_t` for `nclistget` index argument
  Include header for `size_t` in `nclist.h`

Enables potential reuse of module outside of netCDF

Ensures pnetcdf include directory is in path