Added logic to waterfall to ignore re-prompts.
Added logic to waterfall to ignore re-prompts.

yakumo/BotBuilder,stevengum97/BotBuilder,yakumo/BotBuilder,stevengum97/BotBuilder,msft-shahins/BotBuilder,xiangyan99/BotBuilder,yakumo/BotBuilder,stevengum97/BotBuilder,xiangyan99/BotBuilder,xiangyan99/BotBuilder,msft-shahins/BotBuilder,msft-shahins/BotBuilder,xiangyan99/BotBuilder,yakumo/BotBuilder,stevengum97/BotBuilder,msft-shahins/BotBuilder