BwAuthority doesn't come with bwfiles file, and so makes no progress.

I've been running my new freshly-checked-out bwauth for six days, and my periodic cron job tells me:

NOTICE[Mon Mar 04 06:45:01 2013]:No scan results yet.

Mike tells me this means it is making no progress.

I have frequent tracebacks in the logs:

ERROR[Wed Mar 06 17:31:35 2013]:An unexpected error occured.
Traceback (most recent call last):
  File "bwauthority_child.py", line 391, in <module>
    else: main(sys.argv)
  File "bwauthority_child.py", line 331, in main
    min_streams, sql_file)
  File "bwauthority_child.py", line 235, in speedrace
    url = choose_url(start_pct)
  File "bwauthority_child.py", line 105, in choose_url
    f = file("./data/bwfiles", "r")
IOError: [Errno 2] No such file or directory: './data/bwfiles'

This data/bwfiles file is nowhere to be found. It looks like write_file_list() in aggregate.py is what's supposed to generate it. But maybe we only call that function once we have working stats?