Dispatch Queue crashes

[mbap]

Instead of using dispatch queues, which cannot be stopped once they have been queued up, in a future life of the program all dispatch queues should be switched to NSOperationQueues. This will remove a few crash issues inside the app that happen when a dispatch queue is running and the user hits back before it is done. Sometimes the queue is retaining and UIKit element and therefore when it calls on it, and we have popped the view, the element no longer exists, therefore crashing the app.