hdf5

Merge pull request #1387 in HDFFV/hdf5 from ~DEROBINS/hdf5_der:strtok_windows_fix to develop

* commit 'b0457117d867d9850d042d7c3f71a747899b932e':
  Further va_list improvements.
  Added a helpful comment to the va_copy() Windows hack.
  Added a work-around for va_copy() on pre-2013 versions of Visual Studio.