Hugophotoswipe

- Added optional fast mode, with which SmartCrop.py consider less potential
crops (closes issue 10)
- Ensure operational flags (verbose, fast) aren't stored in settings file.

- Added verbose mode

- Use triple-quoted strings in TOML front matter property fields

- Speed improvements by using cached_property
- Cosmetic improvements (progressbar, copyright field)
- Documentation improvements (photo shortcode)

- Bugfix for Windows paths
- Don't include extension in photo name
- Bugfixes for default configurations

Thanks to halogenica for identifying and fixing these bugs!

- Allow for non-album directories
- Add settings file validation