- Add login support for `instagram` ([#195](https://github.com/mikf/gallery-dl/issues/195))
- Add `--no-download` and `extractor.*.download` disable file downloads ([#220](https://github.com/mikf/gallery-dl/issues/220))
- Add `-A/--abort` to specify the number of consecutive download skips before aborting
- Interpret `-1` as infinite retries ([#300](https://github.com/mikf/gallery-dl/issues/300))
- Implement custom log message formats per log-level ([#304](https://github.com/mikf/gallery-dl/issues/304))
- Implement an `mtime` post-processor that sets file modification times according to metadata fields ([#332](https://github.com/mikf/gallery-dl/issues/332))
- Implement a `twitter.content` option to enable tweet text extraction ([#333](https://github.com/mikf/gallery-dl/issues/333), [#338](https://github.com/mikf/gallery-dl/issues/338))
- Enable `date-min/-max/-format` options for `tumblr` ([#337](https://github.com/mikf/gallery-dl/issues/337))
### Changes
- Set file modification times according to their `Last-Modified` header when downloading ([#236](https://github.com/mikf/gallery-dl/issues/236), [#277](https://github.com/mikf/gallery-dl/issues/277))
- Use `--no-mtime` or `downloader.*.mtime` to disable this behavior
- Duplicate download URLs are no longer silently ignored (controllable with `extractor.*.image-unique`)
- Deprecate `--abort-on-skip`
### Fixes
- Retry downloads on OpenSSL exceptions ([#324](https://github.com/mikf/gallery-dl/issues/324))
- Ignore unavailable pins on `sexcom` instead of raising an exception ([#325](https://github.com/mikf/gallery-dl/issues/325))
- Use Firefox's SSL/TLS ciphers to prevent Cloudflare CAPTCHAs ([#342](https://github.com/mikf/gallery-dl/issues/342))
- Improve folder name matching on `deviantart` ([#343](https://github.com/mikf/gallery-dl/issues/343))
- Forward cookies to `youtube-dl` to allow downloading private videos
- Miscellaneous fixes for `35photo`, `500px`, `newgrounds`, `simplyhentai`