[util.sh] Add doc for error function. [util.sh] Add success func. Generalization
[util.sh] Add doc for error function.
[util.sh] Add success func. Generalization

geoffreychiou/industrial_ci,ros-industrial/industrial_ci,tecnalia-advancedmanufacturing-robotics/industrial_ci,tecnalia-advancedmanufacturing-robotics/industrial_ci,ros-industrial/industrial_ci,geoffreychiou/industrial_ci,tecnalia-advancedmanufacturing-robotics/industrial_ci,ros-industrial/industrial_ci