Added a hdf5.vstr dtype
Added a hdf5.vstr dtype

gem/oq-engine,rcgee/oq-hazardlib,gem/oq-hazardlib,gem/oq-hazardlib,vup1120/oq-hazardlib,gem/oq-hazardlib,gem/oq-engine,rcgee/oq-hazardlib,gem/oq-engine,vup1120/oq-hazardlib,vup1120/oq-hazardlib,gem/oq-engine,gem/oq-engine