Virtualize StartEditor and add implementations for the ports that can do it.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@67817 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/gtk/dataview.h

@@ -158,6 +158,8 @@ public:
                           wxDataViewColumn *&column ) const;
     virtual wxRect GetItemRect( const wxDataViewItem &item,
                                 const wxDataViewColumn *column = NULL ) const;
+                                
+    virtual void StartEditor( const wxDataViewItem & item, unsigned int column );
 
     virtual void Expand( const wxDataViewItem & item );
     virtual void Collapse( const wxDataViewItem & item );