Add more depth to the upstart example in host_integration.rst

I found that the original example wasn't starting the docker container when docker is started.  So, I modified it using information I found from https://groups.google.com/forum/#!msg/docker-user/OWz8EOpiXuo/L_uxGFQuYlkJ

Also, upstart wasn't starting docker if it wasn't running ahead of time.  So, I added a change to the docker upstart script to solve this.