- consider slices with slice attribute system=1 to be system slices - don't add the same sliver twice
- consider slices with slice attribute system=1 to be system slices
- don't add the same sliver twice


dreibh/planetlab-lxc-plcapi,dreibh/planetlab-lxc-plcapi,dreibh/planetlab-lxc-plcapi,dreibh/planetlab-lxc-plcapi