Support more AVC-Intra files

Followup to http://thread.gmane.org/gmane.comp.video.ffmpeg.devel/151321
patch by Reimar and Thomas Mundt fixes some AVC-Intra files from
different tickets.
It does not fix http://samples.ffmpeg.org/ffmpeg-


bugs/trac/ticket524/AVCI50.mov

Authors of this commit are: Reimar and Thomas Mundt
Patch and commit message mostly taken from ffmpeg-devel, mail by Carl
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>