added the ability to publish to a redis channel and code improvements

- updated README
- set the channel in the config file
- required the json lib
- tidied up the code in the engine
- renamed local var reading to value in the engine
- renamed local var key to name in the engine
changed the active set to be a key under the namespace called active

- so instead of active set key name "alerts" it would be "alerts.active"
- updated README