Log Message:
gallery-dl: Update to version 1.16.4

Changes:
1.16.4
------
### Additions
 - [furaffinity] add `descriptions` option (#1231)
 - [kemonoparty] add `user` and `post` extractors (#1216)
 - [nozomi] add `num` enumeration index (#1239)
 - [photovogue] added portfolio extractor (#1253)
 - [twitter] match `/i/user/ID` URLs
 - [unsplash] add extractors (#1197)
 - [vipr] add image extractor (#1258)

### Changes
 - [derpibooru] use "Everything" filter by default (#862)

### Fixes
 - [derpibooru] update `date` parsing
 - [foolfuuka] stop search when results are exhausted (#1174)
 - [instagram] fix regex for `/saved` URLs (#1251)
 - [mangadex] update API URLs
 - [mangakakalot] fix extraction
 - [newgrounds] fix flash file extraction (#1257)
 - [sankaku] simplify login process
 - [twitter] fix retries after hitting rate limit