[MPlayer-dev-eng] [PATCH] support for programs in demux_lavf

[Nico Sabbi]

- 1.diff is just cosmetics: the code to parse streams  AVFormatContext 
is moved to a new function with some over-due reformatting.
Unfortunately diff doesn't do a good
job at showing what has change
- 2.diff contains code to fix the passage no (audio|video) to some 
(audio|video)
- 3.diff contains the actual program management code: program
identification, selection and switching