Feed polling is too naïve

07:37 < tibid> New item in AngryDeveloper: angrydeveloper: Yeah but airplanes are flying
               through the air like magic! Trains are just like woo woo.
07:41 < tibid> New item in AngryDeveloper: angrydeveloper: CW: "I just found a random hair on
               my keyboard." AD: "Yeah, I was rubbing my balls all over your keyboard earlier."
07:43 -!- swazi [~<email address hidden>] has left #compsci []
07:47 < tibid> New item in AngryDeveloper: angrydeveloper: Yeah but airplanes are flying
               through the air like magic! Trains are just like woo woo.
07:51 < tibid> New item in AngryDeveloper: angrydeveloper: CW: "I just found a random hair on
               my keyboard." AD: "Yeah, I was rubbing my balls all over your keyboard earlier."
08:01 < tibid> New item in AngryDeveloper: angrydeveloper: Yeah but airplanes are flying
               through the air like magic! Trains are just like woo woo.
08:07 < tibid> New item in AngryDeveloper: angrydeveloper: CW: "I just found a random hair on
               my keyboard." AD: "Yeah, I was rubbing my balls all over your keyboard earlier."

11:00 <@tumbleweed> looks like it's oscillating between announcicng the front and back items
                    in the feed
11:01 <@tumbleweed> i.e. it sometimes gets served the new feed, sometimes the old one

We should do more caching of old results so we don't see these duplicates under odd situations.