Support custom parameters (#76)

* Add the setting icon

* Add support for custom parameters

* Ignore auto generated files

* Update README.md

GPClient/settingsdialog.h

@@ -0,0 +1,25 @@
+#ifndef SETTINGSDIALOG_H
+#define SETTINGSDIALOG_H
+
+#include <QDialog>
+
+namespace Ui {
+class SettingsDialog;
+}
+
+class SettingsDialog : public QDialog
+{
+    Q_OBJECT
+
+public:
+    explicit SettingsDialog(QWidget *parent = nullptr);
+    ~SettingsDialog();
+
+    void setExtraArgs(QString);
+    QString extraArgs();
+
+private:
+    Ui::SettingsDialog *ui;
+};
+
+#endif // SETTINGSDIALOG_H