added clipboard events (wxEVT_COMMAND_TEXT_COPY/CUT/PASTE) and implemented them for wxMSW

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@39141 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/msw/window.h

@@ -332,6 +332,8 @@ public:
 #ifdef __WIN32__
     int HandleMenuChar(int chAccel, WXLPARAM lParam);
 #endif
+    // Create and process a clipboard event specified by type.
+    bool HandleClipboardEvent( WXUINT nMsg );
 
     bool HandleQueryDragIcon(WXHICON *hIcon);