added info on bmi and vsi (owner field)

You will likely need to use the `SoftLayer.utils.lookup` helper when accessing that for two reasons:

* Depending on permissions, not everyone will have access to the billing item information. In that case, this would result in a KeyError exception being thrown here.
* To be able to cleanly split this into multiple lines to match the 80-character PEP-8 limitation.