Add Get/SetDisabledBitmap methods for msw

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/branches/WX_3_0_BRANCH@76588 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

interface/wx/menuitem.h

@@ -163,7 +163,14 @@ public:
         
         @onlyfor{wxmsw}
     */
-    virtual const wxBitmap& GetBitmap() const;
+    virtual const wxBitmap& GetBitmap(bool checked = true) const;
+
+    /**
+        Returns the bitmap to be used for disabled items.
+        
+        @onlyfor{wxmsw}
+    */
+    virtual const wxBitmap& GetDisabledBitmap() const;
     
     /**
         Returns the font associated with the menu item.
@@ -369,6 +376,14 @@ public:
     void SetBitmaps(const wxBitmap& checked,
                     const wxBitmap& unchecked = wxNullBitmap);
 
+    /**
+        Sets the to be used for disabled menu items.
+
+        @onlyfor{wxmsw}
+    */
+    void SetDisabledBitmap(const wxBitmap& disabled);
+
+
     /**
         Sets the font associated with the menu item.