[gtkmm-documentation] Adapt to TreeModelFlags to TreeModel::Flags.

[Murray Cumming <murrayc src gnome org>]

commit 77ff3cc8d1bd4aae1122a2f09714817699eee81c
Author: Murray Cumming <murrayc murrayc com>
Date:   Wed May 3 10:33:38 2017 +0200

    Adapt to TreeModelFlags to TreeModel::Flags.

 .../others/treemodelcustom/exampletreemodel.cc     |    4 ++--
 examples/others/treemodelcustom/exampletreemodel.h |    2 +-
 2 files changed, 3 insertions(+), 3 deletions(-)
---
diff --git a/examples/others/treemodelcustom/exampletreemodel.cc 
b/examples/others/treemodelcustom/exampletreemodel.cc
index 3a792b9..760df9a 100644
--- a/examples/others/treemodelcustom/exampletreemodel.cc
+++ b/examples/others/treemodelcustom/exampletreemodel.cc
@@ -92,9 +92,9 @@ Glib::RefPtr<ExampleTreeModel> ExampleTreeModel::create()
   return Glib::make_refptr_for_instance( new ExampleTreeModel );
 }
 
-Gtk::TreeModelFlags ExampleTreeModel::get_flags_vfunc() const
+Gtk::TreeModel::Flags ExampleTreeModel::get_flags_vfunc() const
 {
-   return Gtk::TreeModelFlags(0);
+   return Gtk::TreeModel::Flags(0);
 }
 
 int ExampleTreeModel::get_n_columns_vfunc() const
diff --git a/examples/others/treemodelcustom/exampletreemodel.h 
b/examples/others/treemodelcustom/exampletreemodel.h
index bc250e3..0fba714 100644
--- a/examples/others/treemodelcustom/exampletreemodel.h
+++ b/examples/others/treemodelcustom/exampletreemodel.h
@@ -38,7 +38,7 @@ public:
 protected:
 
    // Overrides:
-   Gtk::TreeModelFlags get_flags_vfunc() const override;
+   Gtk::TreeModel::Flags get_flags_vfunc() const override;
    int get_n_columns_vfunc() const override;
    GType get_column_type_vfunc(int index) const override;
    void get_value_vfunc(const TreeModel::const_iterator& iter, int column, Glib::ValueBase& value) const 
override;