[gtkmm] demos: Remove calls to deprecated TreeView::set_rules_hint().

[Murray Cumming <murrayc src gnome org>]

commit cc2dfa28443fe0e5031a59d2d5e6a50360a95556
Author: Murray Cumming <murrayc murrayc com>
Date:   Thu Aug 21 20:51:39 2014 +0200

    demos: Remove calls to deprecated TreeView::set_rules_hint().
    
    There is no replacement.

 demos/gtk-demo/example_treeview_editable_cells.cc |    1 -
 demos/gtk-demo/example_treeview_liststore.cc      |    1 -
 demos/gtk-demo/example_treeview_treestore.cc      |    1 -
 3 files changed, 0 insertions(+), 3 deletions(-)
---
diff --git a/demos/gtk-demo/example_treeview_editable_cells.cc 
b/demos/gtk-demo/example_treeview_editable_cells.cc
index 931d7a6..7083402 100644
--- a/demos/gtk-demo/example_treeview_editable_cells.cc
+++ b/demos/gtk-demo/example_treeview_editable_cells.cc
@@ -121,7 +121,6 @@ Example_TreeView_EditableCells::Example_TreeView_EditableCells()
 
   /* create tree view */
   m_TreeView.set_model(m_refListStore);
-  m_TreeView.set_rules_hint();
   Glib::RefPtr<Gtk::TreeSelection> refTreeSelection = m_TreeView.get_selection();
   refTreeSelection->set_mode(Gtk::SELECTION_SINGLE);
 
diff --git a/demos/gtk-demo/example_treeview_liststore.cc b/demos/gtk-demo/example_treeview_liststore.cc
index 14a423f..189539a 100644
--- a/demos/gtk-demo/example_treeview_liststore.cc
+++ b/demos/gtk-demo/example_treeview_liststore.cc
@@ -121,7 +121,6 @@ Example_TreeView_ListStore::Example_TreeView_ListStore()
 
   /* create tree view */
   m_TreeView.set_model(m_refListStore);
-  m_TreeView.set_rules_hint();
   m_TreeView.set_search_column(m_columns.description.index());
 
   add_columns();
diff --git a/demos/gtk-demo/example_treeview_treestore.cc b/demos/gtk-demo/example_treeview_treestore.cc
index 88d2d2b..6a4a2a1 100644
--- a/demos/gtk-demo/example_treeview_treestore.cc
+++ b/demos/gtk-demo/example_treeview_treestore.cc
@@ -165,7 +165,6 @@ Example_TreeView_TreeStore::Example_TreeView_TreeStore()
 
   /* create tree view */
   m_TreeView.set_model(m_refTreeStore);
-  m_TreeView.set_rules_hint();
   Glib::RefPtr<Gtk::TreeSelection> refTreeSelection = m_TreeView.get_selection();
   refTreeSelection->set_mode(Gtk::SELECTION_MULTIPLE);