When coming back from story detail and a more stories request is happening we still want to reload the view with that information after the request has been finished.
added logic to stop any other reload request from starting while next story is loading more stories.
if there is an error send back error.
When coming back from story detail and loading more stories for next story, make sure cell says "Loading More..."

If loading more stories do not let user switch grid/list views.
refresh control should spin if refreshing categories view during first load
Merge pull request #124 from MIT-Mobile/3.6/ipad-news-next-story

3.6/ipad news next story