Deployable workers for doRedis

Hi Bryan, I added a new type of worker to doRedis based on some work I'm currently doing with Simon. My changes allow you to create a "deployable worker" which waits on a single queue for new jobs. When it receives a new job it is deployed a separate queue where it gets tasks from a foreach loop. When it is done it goes back to the job queue and waits for a new job. The extra level of indirection will allow for a load balancer that could manage how many workers a foreach/doRedis loop receives.