[glom/gtkmm4v4] gtkmm4: Adapt to TreeViewColumnSizing as Sizing enum class.

[Murray Cumming <murrayc src gnome org>]

commit 4508624eb79ae5faf250ed25bd0718af0452cac7
Author: Murray Cumming <murrayc murrayc com>
Date:   Fri Apr 28 09:42:19 2017 +0200

    gtkmm4: Adapt to TreeViewColumnSizing as Sizing enum class.

 glom/import_csv/dialog_import_csv.cc  |    2 +-
 glom/mode_data/db_adddel/db_adddel.cc |    4 ++--
 2 files changed, 3 insertions(+), 3 deletions(-)
---
diff --git a/glom/import_csv/dialog_import_csv.cc b/glom/import_csv/dialog_import_csv.cc
index 66ae26e..dc64bda 100644
--- a/glom/import_csv/dialog_import_csv.cc
+++ b/glom/import_csv/dialog_import_csv.cc
@@ -531,7 +531,7 @@ std::unique_ptr<Gtk::TreeViewColumn> Dialog_Import_CSV::create_sample_column(con
   auto cell = create_sample_cell(index);
   col->pack_start(*Gtk::manage(cell.release()), true);
   col->set_cell_data_func(*cell, sigc::bind(sigc::mem_fun(*this, &Dialog_Import_CSV::field_data_func), 
index));
-  col->set_sizing(Gtk::TreeViewColumnSizing::AUTOSIZE);
+  col->set_sizing(Gtk::TreeViewColumn::Sizing::AUTOSIZE);
   return col;
 }
 
diff --git a/glom/mode_data/db_adddel/db_adddel.cc b/glom/mode_data/db_adddel/db_adddel.cc
index 5924a36..779057b 100644
--- a/glom/mode_data/db_adddel/db_adddel.cc
+++ b/glom/mode_data/db_adddel/db_adddel.cc
@@ -660,7 +660,7 @@ void DbAddDel::construct_specified_columns()
     Gtk::Requisition requistion_min, requistion_natural; //TODO: Really support natural size.
     pCellButton->get_preferred_size(m_tree_view, requistion_min, requistion_natural);
 
-    m_treeviewcolumn_button->set_sizing(Gtk::TreeViewColumnSizing::FIXED); //Needed by fixed-height mode.
+    m_treeviewcolumn_button->set_sizing(Gtk::TreeViewColumn::Sizing::FIXED); //Needed by fixed-height mode.
 
     // TODO: I am not sure whether this is always correct. Perhaps, we also
     // have to take into account the xpad property of the cell renderer and
@@ -1649,7 +1649,7 @@ guint DbAddDel::treeview_append_column(const Glib::ustring& title, Gtk::CellRend
 
   //This is needed by fixed-height mode. We get critical warnings otherwise.
   //But we must call set_fixed_width() later or we will have a zero-width column.
-  pViewColumn->set_sizing(Gtk::TreeViewColumnSizing::FIXED);
+  pViewColumn->set_sizing(Gtk::TreeViewColumn::Sizing::FIXED);
 
   auto cols_count = m_tree_view.append_column(*pViewColumn);