Clean up docs somewhat.
Clean up, expand and rearrange a bunch of specs.
Ensure that after setting Que.sleep_period = nil, the wrangler thread doesn't wake a worker one last time.
Spec that the Rails convention of Que.sleep_period = 5.seconds is supported.
Note to self on a future versioning technique for the que_jobs table.
Many tweaks to "Writing Reliable Jobs".
Now that Que.worker_count= automatically sets the mode to :async, we don't need to start with 4 workers when running the que:work rake task.
Rename Que.sleep_period to Que.wake_interval.
Greatly expand and rearrange the documentation.