PUI: fix pui_ani_control, pui_ani_status_update and so on

PUI: fix pui_ani_control, pui_ani_status_update and so on

- pui_ani_control
  stop the animation being played before start playing a new animation
- pui_ani_status_update
  when the status of a animation has been changed, create/send PUI_EVENT_ANI_XXX
  event to notify it to the application
- events removal
  remove events regarding buffer release, frame done
- handle visibility changes
  when the window is fully-obscured and an animation is being played,
  the animation must be stopped
  when the window is unobscured, we must notify application to have
  the opportunity to start again

Change-Id: Icb2b54abaaf4d33a4b337ac477553608e5275aa1
Signed-off-by: Sung-Jin Park <sj76.park@samsung.com>