also fade out fullscreen window using NSAnimation again, to avoid weird effects when switching full screen too quickly
also fade out fullscreen window using NSAnimation again, to avoid weird effects when switching full screen too quickly

git-svn-id: 765db44a9620ed55f4f8addfd3c14fe8cd57f6bb@5921 0fceea05-a30d-0410-8a8b-80ef821fb0a1

nanoant/Skim,nanoant/Skim,nanoant/Skim,nanoant/Skim,nanoant/Skim