include building enclosures as well

There were cases where the building shells overlapped with other
building parts, and weren't being displayed as a result. This also has
the side effect of speeding up the queries.
create indexes to improve query performance
create function to simplify generating indexes
add way_area column and simplify geometries
simplify the previously simplified columns
add columns to aid queries
move statements around and group index creation
road planet_osm_polygon -> planet_osm_line
pre-compute road sort keys
consistent mz_ naming convention for new columns
correct typo when creating index on way_area
generate normalized id for multiple tables
correct table name in update
update queries