hdf5_der

Merge pull request #221 in HDFFV/hdf5 from ~BYRN/hdf5_adb:develop to develop

Buildbot tests passed

* commit '69f975f56792acb9c7a4a8109c43081045b0eafe':
  hdf5 lib needed for extend_dset link.
  Add test lib to extend_dset test link line
  Add hl test dir and test dlib
  Fix h5test.h include issue