Add ability to change cgroup subsystem on running container.

Support get runtime metric(Memory & CPU) of a container.

Add ability to suspend/resume a container.

Fix broken code after merge 0.11.1.

Docker-DCO-1.1-Signed-off-by: kenshin54 <himurakenshin54@gmail.com> (github: kenshin54)
Allow to setup network on the container.

Include static ip address, netmask and gateway.

Docker-DCO-1.1-Signed-off-by: Jialin Tian <himurakenshin54@gmail.com> (github: kenshin54)
Use statistic feature provided by cgroup package as metric info.

Docker-DCO-1.1-Signed-off-by: Jialin Tian <himurakenshin54@gmail.com> (github: kenshin54)
A huge refactor of control cgroup subsystem.

Fix all test.

Docker-DCO-1.1-Signed-off-by: Jialin Tian <himurakenshin54@gmail.com> (github: kenshin54)