Attempt to transition to Vala

src/ag-header-bar.vala

@@ -0,0 +1,13 @@
+namespace Ag {
+
+    class HeaderBar: Gtk.HeaderBar {
+        public void clear()
+        {
+            custom_title = null;
+
+            foreach (Gtk.Widget w in get_children()) {
+                w.hide();
+            }
+        }
+    }
+}

src/widgets.vala

@@ -0,0 +1,13 @@
+namespace Ag {
+
+    public class HeaderBar : Gtk.HeaderBar {
+        public void clear()
+        {
+            custom_title = null;
+
+            foreach (Gtk.Widget w in get_children()) {
+                w.hide();
+            }
+        }
+    }
+}