51 out of 56 - but a typo ate the rss, so now it needs to use a temp
file. (Turns out to be a trivial change to the rssfile constructor
and destruct.) Also looks like we need separate times for "last
changed" and "last seen". This leads to implementing a "fix" command
to update the database format. After commenting out a couple of pages
that don't actually lead to comics anymore, we're now up to 53/53,
36/53 going through check_maybe and the rest being (currently)
singletons. Good enough for now...