submit/tizen/20160824.052737

waylandsink :
1. apply tizen view port.
2. support using full window size for rendering without gst_video_overlay_set_render
3. gst-launch can use full window size for convenient test.
4. Add new property (follow-parent-transform, corp(x, y, w, h) ratio(w, h), scale(w,

Waylandsink : In case of flush buffer, except redraw pending.
waylandsink : remove use_gapless property, add GST_EVENT_CUSTOM_DOWNSTREAM for gapless video playb