added javadoc heading to hdf5 util class
added javadoc heading to hdf5 util class


Former-commit-id: 7c6352ad35cfb9387f2cdcce3305842b6f15e18b [formerly 82600acd7dcd5fe7aa9c085785eb94ea59707732]
Former-commit-id: 80bdf23e843b110451b4e1f194bc06c7858bf6ba
gem/oq-engine,gem/oq-engine,gem/oq-engine,gem/oq-engine,gem/oq-engine