Log Message:
gallery-dl: Update to 1.18.1

Changes:
## 1.18.1 - 2021-07-04
### Additions
- [mangafox] add manga extractor (#1633)
- [mangasee] add chapter and manga extractors
- [mastodon] implement text-posts option (#1569, #1669)
- [seisoparty] add user and post extractors (#1635)
- implement conditional directories (#1394)
- add T format string conversion (#1646)
- document format string syntax

### Changes
- [twitter] set retweet_id for original retweets (#1481)

### Fixes
- [directlink] manually encode Referer URLs (#1647)
- [hiperdex] use domain from input URL
- [kemonoparty] fix username extraction (#1652)
- [kemonoparty] warn about missing DDoS-GUARD cookies
- [twitter] ensure guest tokens are returned as string (#1665)
- [webtoons] match arbitrary language codes (#1643)
- fix depth counter in UrlJob when specifying -g multiple times

## 1.18.0 - 2021-06-19
### Additions
- [foolfuuka] support `archive.wakarimasen.moe` (#1595)
- [mangadex] implement login with username & password (#1535)
- [mangadex] add extractor for a user's followed feed (#1535)
- [pixiv] support fetching privately followed users (#1628)
- implement conditional filenames (#1394)
- implement `filter` option for post processors (#1460)
- add `-T/--terminate` command-line option (#1399)
- add `-P/--postprocessor` command-line option (#1583)

### Changes
- [kemonoparty] update default filenames and archive IDs (#1514)
- [twitter] update default settings
  - change `retweets` and `quoted` options from `true` to `false`
  - change directory format for search results to the same as other extractors
- require an argument for `--clear-cache`

### Fixes
- [500px] update GraphQL queries
- [furaffinity] improve metadata extraction (#1630)
- [hitomi] update image URL generation (#1637)
- [idolcomplex] improve and fix pagination (#1594)
- [instagram] fix login (#1631)
- [instagram] update query hashes
- [mangadex] update to API v5 (#1535)
- [mangafox] improve URL pattern (#1608)
- [oauth] prevent exceptions when reporting errors (#1603)
- [philomena] fix tag escapes handling (#1629)
- [redgifs] update API server address (#1632)
- [sankaku] handle empty tags (#1617)
- [subscribestar] improve attachment filenames (#1609)
- [unsplash] update collections URL pattern (#1627)
- [postprocessor:metadata] handle dicts in `mode:tags` (#1598)

## 1.17.5 - 2021-05-30
### Additions
- [kemonoparty] add `metadata` option (#1548)
- [kemonoparty] add `type` metadata field (#1556)
- [mangapark] recognize v2.mangapark URLs (#1578)
- [patreon] extract user-defined `tags` (#1539)
- [pillowfort] implement login with username & password (#846)
- [pillowfort] add `inline` and `external` options (#846)
- [pixiv] implement `max-posts` option (#1558)
- [pixiv] add `metadata` option (#1551)
- [twitter] add `text-tweets` option (#570)
- [weibo] extend `retweets` option (#1542)
- [postprocessor:ugoira] support using the `image2` demuxer (#1550)
- [postprocessor:ugoira] add `repeat-last-frame` option (#1550)
- support `XDG_CONFIG_HOME` (#1545)
- implement `parent-skip` and `"skip": "terminate"` options \ 
(#1399)

### Changes
- [twitter] resolve `t.co` URLs in `content` (#1532)

### Fixes
- [500px] update query hashes (#1573)
- [aryion] find text posts in `recursive=false` mode (#1568)
- [imagebam] fix extraction of NSFW images (#1534)
- [imgur] update URL patterns (#1561)
- [manganelo] update domain to `manganato.com`
- [reactor] skip deleted/empty posts
- [twitter] add missing retweet media entities (#1555)
- fix ISO 639-1 code for Japanese (`jp` -> `ja`)