add patch split reasoning
suggest asking on ffmpeg-dev if theres doubt about spliting
(and like always if any developer disagrees say so and ill revert this and we can disscuss it on ffmpeg-dev)



git-svn-id: file:///var/local/repositories/ffmpeg/trunk@8412 9553f0bf-9b14-0410-a0b8-cfaf0461ba5b