avcodec/pngdec: add APNG support.

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
avformat/apngdec: add APNG demuxer.

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
avdevice/pulse_audio_common: Use av_freep(), avoid leaving stale pointers

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
avdevice/fbdev_common: Use av_freep(), avoid leaving stale pointers

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
avdevice/avdevice.c: Use av_freep(), avoid leaving stale pointers

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
avcodec/vp6: Use av_freep(), avoid leaving stale pointers

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