Adding gtk_tree_view_column_new_with_area().

Creates a treeviewcolumn using a specific GtkCellArea.
This patch also makes GtkEntryCompletion use the new api
instead of g_object_new().

gtk/gtkentrycompletion.c

@@ -493,7 +493,7 @@ gtk_entry_completion_constructor (GType                    type,
                     completion);
   priv->first_sel_changed = TRUE;
 
-  priv->column = g_object_new (GTK_TYPE_TREE_VIEW_COLUMN, "cell-area", priv->cell_area, NULL);
+  priv->column = gtk_tree_view_column_new_with_area (priv->cell_area);
   gtk_tree_view_append_column (GTK_TREE_VIEW (priv->tree_view), priv->column);
 
   priv->scrolled_window = gtk_scrolled_window_new (NULL, NULL);

gtk/gtktreeviewcolumn.c

@@ -1529,6 +1529,27 @@ gtk_tree_view_column_new (void)
   return tree_column;
 }
 
+/**
+ * gtk_tree_view_column_new_with_area:
+ * @area: the #GtkCellArea that the newly created column should use to layout cells.
+ * 
+ * Creates a new #GtkTreeViewColumn using @area to render it's cells.
+ * 
+ * Return value: A newly created #GtkTreeViewColumn.
+ *
+ * Since: 3.0
+ */
+GtkTreeViewColumn *
+gtk_tree_view_column_new_with_area (GtkCellArea *area)
+{
+  GtkTreeViewColumn *tree_column;
+
+  tree_column = g_object_new (GTK_TYPE_TREE_VIEW_COLUMN, "cell-area", area, NULL);
+
+  return tree_column;
+}
+
+
 /**
  * gtk_tree_view_column_new_with_attributes:
  * @title: The title to set the header to.

gtk/gtktreeviewcolumn.h

@@ -105,6 +105,7 @@ struct _GtkTreeViewColumnClass
 
 GType                   gtk_tree_view_column_get_type            (void) G_GNUC_CONST;
 GtkTreeViewColumn      *gtk_tree_view_column_new                 (void);
+GtkTreeViewColumn      *gtk_tree_view_column_new_with_area       (GtkCellArea             *area);
 GtkTreeViewColumn      *gtk_tree_view_column_new_with_attributes (const gchar             *title,
 								  GtkCellRenderer         *cell,
 								  ...) G_GNUC_NULL_TERMINATED;