lxc-info: Port to LXC API

Signed-off-by: Stéphane Graber <stgraber@ubuntu.com>
Acked-by: Serge E. Hallyn <serge.hallyn@ubuntu.com>
lxc-info: Allow printing IP addresses

This adds a new -i flag to lxc-info to print the container's IP
addresses using get_ips().

Example:
$ lxc-info -n lxc-dev -s -p -i
state:  RUNNING
pid:    21331
ip:     10.0.3.165
ip:     2607:f2c0:f00f:2751:e9ca:842f:efa9:97d1
ip:     2607:f2c0:f00f:2751:216:3eff:fe3a:f1c1

Signed-off-by: Stéphane Graber <stgraber@ubuntu.com>
Acked-by: Serge E. Hallyn <serge.hallyn@ubuntu.com>