ProcessQueue, PriorityQueue, ConcurrencyQueue

Swap package from being for one queue, to many queues under a single namespace.

Initial Release

Basic queue that provides asynchronous processing.

The queue can be started & stopped. It maintains simple stats on the queue (completed, erred, remaining, etc). Customize the number of "concurrent" processors and delay between each "tick" (helpful for not overloading a web server).