[feature] Automatically retry particular failures

[gadicc]

As reported by @maxbauer in #349, and as discussed in many, many, many other issues... Yahoo's servers can be erratic, with a valid request occasionally failing only to work again later (perhaps even on the very next attempt, which may be routed to a different server).

It would be nice to have a feature to automatically retry certain requests, e.g. "401 unauthorized" but not "404 not found".