Fix StormOnDemand require paths

This is a fix for a long term problem. This code should be disappearing
from `fog-core` but until then this has been fixed to correctly
reference the files in `fog-storm_on_demand`

This fixes https://github.com/fog/fog-storm_on_demand/issues/2
billing != monitoring? Just wanted to check in here as it seems like it might be un-intended.