Method setSpecificEngine

gui/src/forms/frmprogress.h:82–84

  void clearSpecificEngine() { getThread.setSpecificEngine(nothing()); }
  void setSpecificEngine(QString engine) {
    getThread.setSpecificEngine(just(engine));
  }

  void setBatchMode(bool value) { batchMode = value; }
  void setBatchLanguages(QString lang, QString langBackup,