I think there's a bug in the delivery code: when daily_maint runs, it
just wipes out the creative content completely before reloading it;
this was once safe (before overflow days) -- now it is not.  In fact,
overflow delivery could run into problems because creatives listed
in the overflow tables at hour 23 on day 1 may not be running on day 2,
and the creative content will be gone.

Another possible hour 0 bug:  when we look at RunningCreatives to gather stats
from the past hour, does RunningCreatives change before we have a chance
to retrieve the stats?  If so, then some creatives' stats will never
be retrieved.

hourly_maint.php:
        various messages

Make reports use date format throughout

Update the i18n libraries

Fix:
 - sample tags generated for direct creative links do not contain
   (h, w) values; they need them

Investigate:
 - what happens to shared memory when creatives/campaigns are edited?
 - are we setting cookies for all delivery mechanisms?  how could we
   suppress this?  how can we use the IDs to calculate unique visitors
   over arbitrary periods?
 - reload_daily() -- do we really need to hold the semaphore while we
   run compute_daily_targets() ?

Document:

