hdf5_der

Merge pull request #179 in HDFFV/hdf5 from ~DEROBINS/hdf5_der:eoc_valgrind_bugfix to develop

Fix for some evict-on-close issues revealed by Valgrind.

* commit 'd3dbe9d90ee71b231b3264e1d62d3efbae3242ef':
  Tentative fix for valgrind issues related to EoC.