winrtrunner should forward output from application

winrtrunner would be a lot more useful if it would do real-time relaying of application output.

This isn't trivial, though. Assumptions:

• Install a qDebug message handler (don't try to do a stdio catch-all)
• Use Windows.ApplicationModel.DataTransfer on Appx to do some generic IPC between the app and winrtrunner.
• Use corecon's TcpTransport API on Windows Phone.
• Integrate the app-side portion inside winmain or a helper library loaded by winmain.