A number of tests against the rate limiter.

It seems that if you have one user waiting between messages:

  x = t × 1.5 + 5

...with t being how much the site asks you to wait, then your timeout
still does climb, but much more slowly.
chatwrapper: Do not simply cross your fingers when sending messages

* Sleep 5 seconds between messages
* When told to wait x seconds, wait 1.5 times as much
  (and then still 5 seconds on success)
* Avoid sending the same message more than once.