changed hdf5 information variables

There are a couple of difficulties here. First, you added the HDF5_DIR, but not the HDF5_INCLUDE_DIRS, which are actually needed to find the headers.
Second, the HDF5_LIBRARY_DIRS just contains "/lib", which in itself is rather useless. Since we know that the HDF5 lib is a sister directory to the include, it works for now by putting in the "/.." as below, but that is again somewhat of a hack, and may not work for installation where, for instance, the headers are in 
/include/hdf5/ and the libraries in /lib/hdf5. 
Third, as @arnaudgelas suggested, we could use (find_package HDF5) to find HDF5 from the HDF5_DIR variable. But that messes up the library renaming and the HDF5_LIBRARY_DIRS still just contains "/lib" then.