fixes for wfrc
Merge branch 'master' into fixes-for-wfrc
sometimes there are vacant units for buildings that don't make it out of the merge

basically the building DOES exist, but when it's merged to nodes, some of the node_ids are missing because there are parcel_ids in the building table that don't exist in the parcels.index.

anyway, at this point we deal with the issue appropriately and print a warning so this shouldn't come up again.
allow only_built to be set to false