v0.20.0

Changelog

• f579c3d Cleanups
• f08838e Package refactoring and cleanup
• e424767 Performance and concurrency optimization
• efb5e4b Cleanup visualize.js
• 65e46c9 Change in requirements occurrences behavior
• 165964b New quirk: capabilities.occurrences.permissive
• 0969f3c in_range: special case when applied to a range
• 0426e1b node_filter: properties as sequenced list, not map
• 45af514 Upgrade dependencies