Improve performance for drag and drop

- Changing the style sheets for the selection frame dynamically considerably
  slowed down the handling of the mouse events.
  Instead two separate widgets with fixed style sheets are now used.
- Recreating the macro segments after dropping a widget took too much
  time leading to unresponsive drop operations

src/headers/advanced-scene-switcher.hpp

@@ -298,8 +298,6 @@ public slots:
 	void on_close_clicked();
 
 private:
-	void SetSelection(MacroSegmentList *, int);
-
 	MacroSegmentList *conditionsList = nullptr;
 	MacroSegmentList *actionsList = nullptr;
 

src/headers/macro-segment.hpp

@@ -62,8 +62,10 @@ signals:
 protected:
 	Section *_section;
 	QLabel *_headerInfo;
-	QFrame *_frame;
-	QVBoxLayout *_selectionFrameLayout;
+	QWidget *_frame;
+	QFrame *_noBorderframe;
+	QFrame *_borderFrame;
+	QVBoxLayout *_contentLayout;
 
 private:
 	virtual MacroSegment *Data() = 0;