Added ComboBoxDelegate class and using it as delegate for type columns in table view.

UIs/BeetRoundWidgets/mainwindow.h

@@ -7,8 +7,8 @@
 QT_BEGIN_NAMESPACE
 
 class QUndoStack;
-
 class QUndoView;
+
 namespace Ui {
 class MainWindow;
 }
@@ -110,6 +110,7 @@ class MainWindow : public QMainWindow {
   unique_ptr<EditItemDialog> m_editItemDialog;
 
   /// Setup functions
+  void setupModelViews();
   void createActions();
   void createFileActions();
   void createUndoActions();