This uses the renamed DataView serviceStatus instead of the former
status and fixes the problem that CLI still assumed to have fetch
and count function on the DataView.
fixes#6777
Prior to this change the PerfdataSet only knew the labels of a performance
data value which prevented the Perfdata object from being used
individually.
refs #6515
Instead of having two separate functions to get the prefix
and the formatted time interval the new functions return
both the prefix and the time interval.
refs #5981