- if /vservers/sliver does not exist (but /etc/passwd entry does),   create it - call vuseradd with -t option if vref is specified
- if /vservers/sliver does not exist (but /etc/passwd entry does),
  create it
- call vuseradd with -t option if vref is specified


planetlab/NodeManager,dreibh/planetlab-lxc-nodemanager,planetlab/NodeManager,dreibh/planetlab-lxc-nodemanager,dreibh/planetlab-lxc-nodemanager,planetlab/NodeManager,planetlab/NodeManager