Qt5 fixes

Fixes compilation and running of QUpgrade on Windows VS2010. Note that these are only compile-time fixes, I don't have hardware to test this. And the watching of serial ports functionality is gone. It should be re-added by using a time to repeatedly call `QSerialPortInfo::availablePorts()` and to watch for a `QSerialPort::ResourceError` from serial ports that are in use in case they are disconnected.