Remove the stale metar.tbl and zonecatalog.curr.tar, which the USA
NWS hasn't been updating for many years, and add the public domain
airports.csv file from the amazing ourairports.com community. Also
update to latest (2019) USA Census Bureau location data, March 2020
WX zone information, cooperative sites list from 2018 (latest), and
regenerated active station and zone lists. Loss of the zonecatalog
necessitates directly applying various forecast and alert URL
patterns, though some which appeared unused by NWS for many years
were not included.
Clear out all old overrides, since the vast majority are obsoleted
by refreshed data, and build fresh correlation sets from the above
sources. Basically all sites have switched from HTTP to HTTPS, so
update URLs for this too.
