Redis error

I was unable to attach an onError handler to the raw redis connection, so when we lost connectivity to redis,  the node app would just kick up a fuss, I wanted to be able to deal with that how I wanted. While I was at it, I added the possibility of listening for onReady so that you can also have your own logic for when the connection is ready.

I also made it so that when on error gets called, we pass back the raw connection so that you can say, listen for ready again and know that you've reconnected.