Don't use deprecated wxDataViewCtrl::StartEditor() in the sample.

Also document this deprecation in the change log and explain how to update the
existing code.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@70575 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

samples/dataview/dataview.cpp

@@ -1170,7 +1170,7 @@ void MyFrame::OnAddTreeItem(wxCommandEvent& WXUNUSED(event))
     if (ctrl->IsContainer(selected)) {
         wxDataViewItem newitem = ctrl->AppendItem( selected, "Item", 0 );
         ctrl->Select(newitem);
-        ctrl->StartEditor(newitem, 0);
+        ctrl->EditItem(newitem, ctrl->GetColumn(0));
     }
 }