Original commit message from CVS: * gst/debug/gstnavigationtest.c: (gst_navigationtest_class_init), (gst_navigationtest_handle_src_event), (draw_box_planar411), (gst_navigationtest_planar411), (gst_navigationtest_change_state): * gst/debug/gstnavigationtest.h: make navigationtest display button-press and button-release events