Replace FFmpeg with Libav in licence headers
Signed-off-by: Mans Rullgard <email@example.com>
Make ff_inverse stay with libavutil, and optional copy it to libavcodec.
The ff_inverse table is used by FASTDIV macro, defined in libavutil, but upto now the table was defined only in libavcodec.
After this change, the main copy of ff_inverse is part of libavutil (just...