Add missing HLS MIME type: audio/mpegurl
Update FFmpeg to version 7.1.1, carrying the same patches, and one new
patch: Implementing support for HLS ID3 tags changing mid-stream.
We cannot do away with fdk-aac yet, because the USAC codec is missing
features that fdk-aac implements already.
Fixes#428
Signed-off-by: Christopher Snowhill <kode54@gmail.com>