Update pending list management code

Update pending list management code

if the dbox is not shown yet (not the pause,resume event).
do not append it to pending list.

instead of pending list, add it to hidden list.
so if it is shown (render buffer is ready to draw something one it, in case of script type),
move it to the pending list from hidden list.

so while creating a render buffer from master,
the livebox will not do busy waiting now.

just it will do update again when it gets shown.
(move from hidden_list to pending_list)

Change-Id: I880dba72602dd287e3814d28e7113aba8708519b