Fixes for F16.

cgroup is now mounted automatcially by systemd and the way is mounted is
very different from before. Hence, cgroups.py needs to be changed to
reflect the new mount point, and it doesn't use inotify to monitor the
FS anymore. Everything is done dynamically at runtime.

Changes for Coresched are cgroups related.

Since /var is mounted on tmpfs, os.rename doesn't work across partition,
so shutil.move is used instead.