84756982e9
- split 'user' extractor and its 'avatar' and 'background' options into
separate extractors ('artworks', 'avatar', 'background')
- avatars can now be downloaded with
https://www.pixiv.net/en/users/ID/avatar
as URL and will use a proper archive key; similar for backgrounds
- options for the 'user' subcategory must be moved to 'artworks' to have
the same effect as before