message: Use a variable to hold list of user-tunable CMake options.
  Fixes
diff: @@ -99,8 +99,10 @@ if(ADIOS2_HAVE_MPI)
  add_definitions(-DOMPI_SKIP_MPICXX -DMPICH_SKIP_MPICXX)
  endif()
  -GenerateADIOSHeaderConfig(MPI ZFP BZip2 ADIOS1 HDF5 DataMan Python Fortran
  - SysVShMem)
  +set(ADIOS2_CONFIG_OPTS
  + BZip2 ZFP MPI DataMan ZeroMQ HDF5 ADIOS1 Python Fortran SysVShMem
  +)
  +GenerateADIOSHeaderConfig(${ADIOS2_CONFIG_OPTS})
  install(FILES ${ADIOS2_BINARY_DIR}/source/adios2/ADIOSConfig.h
  DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}/adios2
  @@ -188,7 +190,7 @@ message(" Build Type: ${CMAKE_BUILD_TYPE}")
  message(" Testing: ${BUILD_TESTING}")
  message(" Build Options:")
  -foreach(opt BZip2 ZFP MPI DataMan ZeroMQ HDF5 ADIOS1 Python Fortran SysVShMem)
  +foreach(opt IN LISTS ADIOS2_CONFIG_OPTS)
  message_pad(" ${opt}" 15 label)
  if(${ADIOS2_HAVE_${opt}})
  message("${label}: ON")
  