1. Init and fini wakeup handler during screen init/fini instead of preinit
   The frequent screen init/close will happen when the user do the test with
 only "X", that will trigger the wakeup handler does not take effect, 
 then some VBLANK events will not be obtained.
2. Update damage region only in the "exchange buffer" case
   there is no need to report damage in other flip/blit case in swapbuffer,
and we only need to report it when the app wants to notify the composite manager. 
   Otherwise, some pontential issues will happen in some versions of X

Change-Id: Ic0c73bc5f0bc6c24d5a31cf48e814af2d994c7f5