hdf5_plugins

Merge pull request #13 in TEST/hdf5_plugins from ~BYRN/hdf5_plugins_adb:master to master

* commit '759d9ff6add52ea2cbf4888258d2b014b9ceffd7':
  Correct usage of vars in example build and test
  fix plugin binary example cmake code
  Need add_executable statement for h5repack
  Correct variable for hdf5 install
  Fix HDF5 and plugin install location