attached picture

[Martin Obreshkov]

Hi i've just started with taglib a few days ago and for now it works
fine. I am working on a function to extract artowrks from a file if
the file is MPEG with ID3v2 tag  TagLib::ID3v2::AttachedPictureFrame
do the job but how can i do that for MP4 fie formats. I have try doing
it by using TagLib::MP4::Tag::itemListMap but there is no item for
picture frame so any suggestions how to do it? :)