- reuse cls_containerize.Containerize.PullImage()
- pass parameter directly instead of indirectly via class
- always read node name and use this instead of "sometimes" looking it
  up from a class member. With "sometimes" I mean that if no node name
  is given, it will take it from self.eNBIPAddress, which is confusing
  at best if we can give the node name directly
- consistently put the node name in the xml file