Link AvogadroIO to HDF5 target

Rather than using HDF5_LIBRARIES ( which seems to
point to a DLL ) using the hdf5 imported target.

Change-Id: I4e6b8678b448049a37a9bc752dae4ad36933f9b7
Merge topic 'hdf5-windows-fix' into master

c15edfbc Link AvogadroIO to HDF5 target