Provide an Anti-spamming mechanism.

[sjqnn]

For hear rules, allow bot creators to limit a bot from responding multiple times in the same thread. In the case that a bot doesn't accurately answer a user's question with it's first response, provide a mechanism to prevent the bot from chiming in additional times in a thread. I don't know how we'd want to implement this exactly, but I think it would be a nice configurable thing we could include.