examples: Add navigation test to video-sink
examples: Add navigation test to video-sink

http://bugzilla.clutter-project.org/show_bug.cgi?id=2624

GNOME/clutter-gst,ystreet/clutter-gst,lubosz/clutter-gst,ystreet/clutter-gst,GNOME/clutter-gst,GNOME/clutter-gst,GNOME/clutter-gst,ystreet/clutter-gst,ystreet/clutter-gst,lubosz/clutter-gst,skinkie/clutter-gst,skinkie/clutter-gst,skinkie/clutter-gst,lubosz/clutter-gst