Additions
- [imagechest] add new extractor for imgchest.com ([750](https://github.com/mikf/gallery-dl/issues/750))
- [instagram] add `post_url`, `tags`, `location`, `tagged_users` metadata ([743](https://github.com/mikf/gallery-dl/issues/743))
- [redgifs] add image extractor ([724](https://github.com/mikf/gallery-dl/issues/724))
- [webtoons] add new extractor for webtoons.com ([761](https://github.com/mikf/gallery-dl/issues/761))
- implement `--write-pages` option ([736](https://github.com/mikf/gallery-dl/issues/736))
- extend `path-restrict` option ([662](https://github.com/mikf/gallery-dl/issues/662))
- implement `path-replace` option ([662](https://github.com/mikf/gallery-dl/issues/662), [#755](https://github.com/mikf/gallery-dl/issues/755))
- make `path` and `keywords` available in logging messages ([574](https://github.com/mikf/gallery-dl/issues/574), [#575](https://github.com/mikf/gallery-dl/issues/575))
Changes
- [danbooru] change default value of `ugoira` to `false`
- [downloader:ytdl] change default value of `forward-cookies` to `false`
- [downloader:ytdl] fix file extensions when merging into `.mkv` ([720](https://github.com/mikf/gallery-dl/issues/720))
- write OAuth tokens to cache ([616](https://github.com/mikf/gallery-dl/issues/616))
- use `%APPDATA%\gallery-dl` for config files and cache on Windows
- use `util.Formatter` for formatting logging messages
- reuse HTTP connections from parent extractors
Fixes
- [deviantart] use private access tokens for Journals ([738](https://github.com/mikf/gallery-dl/issues/738))
- [gelbooru] simplify and fix pool extraction
- [imgur] fix extraction of animated images without `mp4` entry
- [imgur] treat `/t/unmuted/` URLs as galleries
- [instagram] fix login with username & password ([756](https://github.com/mikf/gallery-dl/issues/756), [#771](https://github.com/mikf/gallery-dl/issues/771), [#797](https://github.com/mikf/gallery-dl/issues/797), [#803](https://github.com/mikf/gallery-dl/issues/803))
- [reddit] don't send OAuth headers for file downloads ([729](https://github.com/mikf/gallery-dl/issues/729))
- fix/improve Cloudflare bypass code ([728](https://github.com/mikf/gallery-dl/issues/728), [#757](https://github.com/mikf/gallery-dl/issues/757))
- reset filenames on empty file extensions ([733](https://github.com/mikf/gallery-dl/issues/733))