Post #84

https://github.com/python-telegram-bot/python-telegram-bot/pull/331 To hold a conversation with users, the #bot has to implement a #state machine to keep track of the different paths in the #conversation. This is a pretty common pattern and we don't have a good way to deal with it right now. The #state_machine_bot.py example is far from perfect. This PR introduces a new Handler subclass called ConversationHandler to take care of this. Instead of re-inventing the wheel, this handler acts only as "management" for the existing handler classes. Copied from documentation: A handler to hold a conversation with a user by managing four collections of other handlers. The first collection, a list named entry_points, is used to initiate the conversation, for example with a CommandHandler or RegexHandler.