Release v1.3.0

Release v1.2.0

Release v1.1.0

Release v1.0.0

The first stable release. Locks the public API surface; v1.x patches
remain compatible. Built and published from a70c343.

See CHANGELOG.md for full release notes and docs/migration-0.1-to-1.0.md
for the v0.1 to v1.0 migration guide.