Backgrounded invokeDelayedProcessing

Doing this intensive method causes upwards of 3 full seconds of UI
freeze. There's nothing in there except presenting the `UIAlertView`
that needs to happen on the main thread. Wrapping most of the
function in a `dispatch_async` fixes a freeze on startup or wake
that our team had experienced a lot.
![screen shot 2014-05-03 at 10 55 26 pm](https://cloud.githubusercontent.com/assets/853032/2872086/b29c0cb0-d340-11e3-9b07-bdd93f2988cf.png)