libcgroup: Added new package.

libcgroup: Added new package.

libcgroup also contains cgroup-utils, which make it very handy to work
with user defined cgroups settings.
It let's you define cgroups in a json like config file and execute them on the cmdline.

Example:

/etc/cgroup.conf:
----------------
group lowbob {
        cpu { cpu.shares="1"; }
        cpuacct { cpuset.cpu = "0" }
        memory { memory.limit_in_bytes = 10m; }
        blkio { ... }
	...
}
----------------
cgconfigparser -l /etc/cgroup.conf
cgexec -g cpu,memory,blkio:/lowbob cpuintense-task

Signed-off-by: Daniel Danzberger <redacted>