Developers have seen references to the next-generation iPhone and iOS 7 in app usage logs, according to a new report. One particular developer noted Apple has been testing hardware identified as “iPhone 6.1,” powered by a device running iOS 7. The iPhone 5 is identified as either “iPhone 5.1” or “iPhone 5.2,” depending on the model and 4G band. Because the developer app requests come from an Apple Cupertino IP address,…