Support LXC (cont.)

This commit can run lxc-create for LXC instance.
However it can't run lxc-start with following error.

$ sudo lxc-start -n lxc1
lxc-start: failed to attach 'veth80CK6J' to the bridge 'br0' : Operation not supported
lxc-start: failed to create netdev
lxc-start: failed to create the network
lxc-start: failed to spawn 'lxc1'
lxc-start: The container failed to start.
lxc-start: Additional information can be obtained by setting the --logfile and --log-priority options.
Bootable LXC instance, however using DHCP client and sshd...
Off sshd service
Revert "Off sshd service"

This reverts commit 338ecaf48e63825d62009f4f5c08cb7c7cd17a60.
Merge branch 'master' into feature/dhcp_lxc_on_openvnet
Merge pull request #42 from master-q/feature/dhcp_lxc_on_openvnet

Support LXC instance (part.1)