title: Dynamic cell height in iOS 7 and iOS 8 - can I only support heightForRowAtIndexPath in iOS 7?
body: <p>I have a table view with dynamically sized cells. This works great in iOS 8 but it's not supported in iOS 7. I'm required to implement tableView:heightForRowAtIndexPath or the app will crash in iOS 7. If I do that, I'm going to have to calculate the height of the cell. The problem is that if I implement this method, iOS 8 pays attention to it and no longer does its dynamically sized cell magic. Is there any way to only implement this method for iOS 7 clients?</p>