broadcast: explore sub-state-machine that the starting states would use to transition youtube to live state

We currently have the doStatusActions function from the "broadcast" package which is responsible for taking the YouTube broadcast object through a series of checks and transitions to get it into the live state. The problem with this is that it requires use of a go routine to keep it running in the background so that we can return from the handler (GAE will restart a service if a handler does not return within some given amount of time). We should consider having a sub-state machine that our starting states can utilise that will follow the same pattern as our other state machines i.e. not active between calls to the handlers.