Ytcc

- Add `reverse` command, and add `--reverse` flag to `subscribe` command (86)
- Fix duplicated youtube-dl log messages
- Fix crash on invalid return values from youtube-dl (87)
- Fix playlist attributes filter
- Fix exit codes on error

* Add `restrict_filenames` and `max_duration` config options
* Add RSS printer (`--output rss`) to generate a video feed
* Add `umark` subcommand and key-binding to ytccf.sh
* Add `--order-by` option to `list` subcommand
* Changed watched status from simple yes/no flag to date
* Changed behavior of `--watched` option and added `--unwatched` option. `--watched` now lists *only* watched videos and not *all* videos. To list all videos use both `--watched --unwatched`.

- Fix cleanup command
- Add ytccf.sh script to setup.py (and therefore also to the pypi.org package)
- Improve autocompletion

**This release is not backwards compatible with older releases**. Check the [migration docs](https://github.com/woefe/ytcc/blob/master/doc/migrate.md) to migrate your old subscriptions.

New features and changes:

- New ytcc command structure. See `ytcc --help` to get started
- Support for platforms other than YouTube: ytcc now is based on youtube-dl's playlist features. (7)
- A tagging feature has been added for easier categorization of subscriptions (23)
- Windows (10) support
- The ytcc command now supports reading IDs from stdin, which makes it more reusable. See the [ytccf](https://github.com/woefe/ytcc/blob/master/scripts/ytccf.sh) script based on fzf for an alternative terminal user interface
- Improved startup time
- Video duration (25)
- JSON output
- Fixed wide character support in printed tables (62)
- Dropped support for Python 3.6

- Windows support
- Fixed some crashes
- Python 3.7 support
- Faster startup

Tons of new stuff