Added test-mode. Added aux. function isSerialOpen().

update.h

@@ -31,6 +31,7 @@ class Update : public QObject {
     QFile m_update_ctrl_file_copy;
     QString m_workingDir;
     bool m_maintenanceMode;
+    bool m_testMode;
 
     bool m_init;
 
@@ -51,6 +52,7 @@ public:
                     QString update_ctrl_file,
                     QString workingDir = ".",
                     bool maintenanceMode = false,
+                    bool testMode = false,
                     QObject *parent = nullptr,
                     char const *serialInterface = SERIAL_PORT,
                     char const *baudrate = "115200");
@@ -69,6 +71,7 @@ private:
     bool stopBootloader() const;
     bool openSerial(int br, QString baudrate, QString comPort) const;
     void closeSerial() const;
+    bool isSerialOpen() const;
     bool resetDeviceController() const;
     QByteArray loadBinaryDCFile(QString filename) const;
     bool downloadBinaryToDC(QString const &bFile) const;