doc/codecs: document ignore_err

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
avcodec: add AV_EF_IGNORE_ERR

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
avformat: add AV_EF_IGNORE_ERR

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
avcodec/h263dec: use AV_EF_IGNORE_ERR

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>