hdf5_ep

Merge pull request #826 in HDFFV/hdf5 from ~BYRN/hdf5_adb:develop to develop

* commit 'e94ed99c5bf7c4ae5df56f75606ef1b486e16bb2':
  Add HD prefix
  HDFFV-9724 Remove VDS file cache functionality
  Removed incorrect MPI text
  Par example needs to link with mpi libs
  Because of MPI requirements in library ALWAYS add include path
  Cleanup comments and if() in TRY blocks
  Skip test if 1.6 API
  HDFFV-9724 Add ENV VAR to vds test
  HDFFV-9724 Copy efc_open search from Lextern_traverse
  Add prefix dir to the clear command
  HDFFV-9724 Add H5LS prefix test with ${ORIGIN}
  Add h5dump VDS prefix tests
  HDFFV-9724 combine efc and vds into one function
  Correct var name
  Fix VDS file cache var names
  Remove return from void functions
  Added java wrappers and tests
  HDFFV-9724 Initial changes and test
  Changed reference from dl to CMake variable
  H5detect and H5make_libsettings need include folder