Add back building attributes as they are being built-up
The building attributes of the legacy database are:
column_name | data_type
-----------------+-----------------------------
osm_id | bigint
z_order | integer
geometry | geometry(Geometry,900913)
building | text
building_use | text
building_levels | text
amenity | text
occupancy | text
position | text
floor_space | double precision
last_modified | timestamp without time zone
area | double precision
Let's add them back, one by one as we need them (have a rabotnik
rule that populates them).