FIX #90 by 1. replacing _safe_key in pprint and 2. handling of non-existant perf counters
FIX #90 by 1. replacing _safe_key in pprint and 2. handling of non-existant perf counters

RRZE-HPC/kerncraft,RRZE-HPC/kerncraft,RRZE-HPC/kerncraft,cod3monk/kerncraft,cod3monk/kerncraft