Use enum explicitly constructor as default values

This will avoid problems generating python bindings, shiboken does not
handle well '{}' initialization.

src/DockWidget.h

@@ -56,7 +56,7 @@ public:
      * when visible, or stays without a parent when hidden. This allows to support docking
      * to different main windows.
      */
-    explicit DockWidget(const QString &uniqueName, Options options = {});
+    explicit DockWidget(const QString &uniqueName, Options options = DockWidgetBase::Options());
 
     ///@brief destructor
     ~DockWidget() override;

src/DockWidgetBase.h

@@ -86,7 +86,7 @@ public:
      * There's no parent argument. The DockWidget is either parented to FloatingWindow or MainWindow
      * when visible, or stays without a parent when hidden.
      */
-    explicit DockWidgetBase(const QString &uniqueName, Options options = {});
+    explicit DockWidgetBase(const QString &uniqueName, Options options = DockWidgetBase::Options());
 
     ///@brief destructor
     ~DockWidgetBase() override;

src/MainWindow.h

@@ -49,7 +49,7 @@ public:
     ///@param parent QObject *parent to pass to QMainWindow constructor.
     ///@param flags Window flags to  pass to QMainWindow constructor.
     explicit MainWindow(const QString &uniqueName, MainWindowOptions options = MainWindowOption_None,
-                        QWidget *parent = nullptr, Qt::WindowFlags flags = {});
+                        QWidget *parent = nullptr, Qt::WindowFlags flags = Qt::WindowFlags());
 
     ///@brief Destructor
     ~MainWindow() override;

src/MainWindowBase.h

@@ -57,7 +57,7 @@ class DOCKS_EXPORT MainWindowBase : public QMainWindowOrQuick
 public:
     typedef QVector<MainWindowBase*> List;
     explicit MainWindowBase(const QString &uniqueName, MainWindowOptions options = MainWindowOption_HasCentralFrame,
-                            QWidgetOrQuick *parent = nullptr, Qt::WindowFlags flags = {});
+                            QWidgetOrQuick *parent = nullptr, Qt::WindowFlags flags = Qt::WindowFlags());
 
     ~MainWindowBase() override;
 
@@ -79,7 +79,7 @@ public:
      */
     void addDockWidget(DockWidgetBase *dockWidget,
                        KDDockWidgets::Location location,
-                       DockWidgetBase *relativeTo = nullptr, AddingOption option = {});
+                       DockWidgetBase *relativeTo = nullptr, AddingOption option = KDDockWidgets::AddingOption());
 
     /**
      * @brief Returns the unique name that was passed via constructor.