New code unearthed in watchOS 4.3.1 by 9to5Mac suggests the possibility that Apple may be at least considering opening up the development of Apple Watch faces to third party developers — something that many have been asking for almost since the wearable device first debuted. Code found in the NanoTimeKit framework that’s responsible for handling watch faces, includes a log message in the process that communicates with Xcode on macOS, declaring…