AVRProcessor: renamed finished() signal to stopped() to avoid confusion with
QThread::finished(), new stop() slot, new loadFirmware() replaces load(), for
simplicity with qt signals.
AbstractPin: new pin concept, these classes provide an interface to the simavr IRQ system
AbstractPinFactory: new pin factory classes help distribute pins to external
components
MainWindow: new main window widget, all component initiation moved to mainwindow