stream_results was flakey for me, so I switched to using a cursor from raw_connection()

We definitely definitely do not want SQLAlchemy nor anything else buffering the results
because we want to read them only long enough to stream them to the web.
It's sort of looking like I should ditch SQLAlchemy and just use psycopg2 directly.
Musings on next steps
Switch to using the logging module.

Also, localize connections; instead of a global C,
have a C where its actually used.
The logging pointed out to me that I was closing C once I was done
commandeering the DB, but Changes needs it until its lifetime is
over--which is supposed to be never, ideally. I realized this is silly
and just reconnected to the DB as needed (which isn't so bad, really).