Rate-limit chiron

[dehnert]

Some kind of rate-limit to reduce people's tendency to play with chiron seems desirable. It's not clear how exactly this should work, since I think pasting a bunch of tickets on -c debathena is pretty common. Some possibilities:

• limit only certain fetchers/matchers (Debathena #xxx is probably pretty safe, but XXX Airport is more likely to get played with)
• limit only certain classes (I think people tend to behave better on -c debathena than -c sipb)
• limit messages, not tickets -- bulk lookups tend to be one zephyr, and playing (at least when annoying) tends to be spread out (though I'm less sure this is a good enough distinguisher)

To some degree, Chiron-#18 is a substitute for this.

[dehnert]

jhawk suggests when the rate-limit triggers, chiron could move to the .d. I'm dubious that talking on sipb.d would really make people much happier than sipb (and jhawk is also unsure), but it's a possible experiment.