

code clean-up

added calls to PAPI_describe_event
        and to PAPI_query_event [this one inside comment, awaiting
                                 finishing all the query interfaces]
to check for valid values in PAPI_start_counters

pyrovski/papi,pyrovski/papi,pyrovski/papi,pyrovski/papi,pyrovski/papi,arm-hpc/papi,arm-hpc/papi,arm-hpc/papi,arm-hpc/papi,pyrovski/papi,arm-hpc/papi,pyrovski/papi,pyrovski/papi,arm-hpc/papi,arm-hpc/papi