Ordering using generic views only by date, not by time

[dokterbob]

As the occult fascism of Django's generic views does not allow for overriding the sorting method used, for now we'll have to do with posts being ordered by just the date.

But this should not last for long: as soon as a decent class based (generic) views implementation will reach a somewhat stable level, I will migrate to using these and save myself tons of headaches.