Some changes I've made when work on my Twitter client TwiMeido

[rainux]

• Provide a no_data callback for no data received in 90 secs According to Twitter User Stream API doc, we should reconnect automatically when no data received in 90 secs, this is OK since Twitter will push blank lines for connection keep alive. But the EventMachine::Connection#reconnect has issues explained in http://goo.gl/LfpnG, I workaround it by provide a no_data callback, and just re-create the User Stream connection in application level.
• Provide callbacks for HTTP 401 & HTTP 420\ With unauthorized callback, we can do things like clear User's access token to avoid meaningless retry in the future, in application level.
• Should stop on unexpected errors It's meaningless to keep the connection when unexpected errors occurred.

[rud]

Feel free to create a new pull-request based current master