Add forgotten AVC Intra entry to Changelog.
mjpegdec: allow 2 components in ljpeg_decode_yuv_scan()

Fixes assertion failure

Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
oggparseskeleton: Check the overall start time before using it.

Fixes division by zero

Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>