Improve readability of worker function
Remove unused variable from season function
Fix bug causing infinite loop in _download_game thread worker
Simplify logging output
Remove default timeout

The season function takes twice as long (2 min) as it used to (1 min). I'm not
sure why, but I suspect there's at least a little lock contention with the
logger, but I can't imagine that doubles the amount of time.
Halve the default number of threads

After some manual tests, I think the season function gets a boost out of going
from cpu_count() - 1 to cpu_count() threads, but no boost thereafter.
Fix inability to find favored team on older-season games

Instead of grabbing the big 'WAS -4.0' in the middle of the page, look at the
sub header at the top of the page where it says 'Odds: Washington by 4'.