* cpustatMetric.go: Use derived values instead of absolute values
The values in /proc/stat are absolute counters related to the boot
time of the system. To obtain a utilization of the CPU, the changes
in the counters must be derived according to time. To take only the
absolute values leads to the fact that changes in the utilization,
straight with larger values, do not become visible.
* Add new collector for /proc/schedstat
The `schedstat` collector reads data from /proc/schedstat and calculates
a load value, separated by hwthread. This might be useful to detect bad
cpu pinning on shared nodes etc.
Co-authored-by: Michael Schwarz <post@michael-schwarz.name>
