Implement lxc.rootfs.options

Signed-off-by: Stéphane Graber <stgraber@ubuntu.com>
upstart: Make sure FORWARD is allowed for containers

Signed-off-by: Stéphane Graber <stgraber@ubuntu.com>
lxc_info: Fix -H with -c

Signed-off-by: Stéphane Graber <stgraber@ubuntu.com>