CpuStats.CpuUsage includes TotalUsage

Docker-DCO-1.1-Signed-off-by: Bernerd Schaefer <bj.schaefer@gmail.com> (github: bernerdschaefer)
Replacing docker-dev with libcontainer mailing list.

Docker-DCO-1.1-Signed-off-by: Victor Marmol <vmarmol@google.com> (github: vmarmol)
Merge pull request #34 from bernerdschaefer/cgroup-stats-total-cpu-usage

CpuStats.CpuUsage includes TotalUsage
Merge pull request #35 from vmarmol/fixes

Replacing docker-dev with libcontainer mailing list.
Add systemd stats, reusing fs stats functionality