GtkWidget: Add gtk_widget_get_path().

This function composes and returns a GtkWidgetPath representing
the passed widget.

gtk/gtkwidget.h

@@ -37,6 +37,7 @@
 #include <gtk/gtkstyle.h>
 #include <gtk/gtksettings.h>
 #include <gtk/gtkstylecontext.h>
+#include <gtk/gtkwidgetpath.h>
 #include <atk/atk.h>
 
 G_BEGIN_DECLS
@@ -944,6 +945,8 @@ gboolean     gtk_widget_in_destruction (GtkWidget *widget);
 
 GtkStyleContext * gtk_widget_get_style_context (GtkWidget *widget);
 
+GtkWidgetPath *   gtk_widget_get_path (GtkWidget *widget);
+
 
 G_END_DECLS