Add some more missing stubs to the osx webkit backend.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/branches/SOC2011_WEBVIEW@68172 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/osx/webview_webkit.h

@@ -90,6 +90,14 @@ public:
     virtual void Undo() {}
     virtual void Redo() {}
 
+    //Clipboard functions
+    virtual bool CanCut() {}
+    virtual bool CanCopy() {}
+    virtual bool CanPaste() {}
+    virtual void Cut() {}
+    virtual void Copy() {}
+    virtual void Paste() {}
+
     // ---- methods not from the parent (common) interface
     wxString GetSelectedText();