v3.0.0

What's Changed

• Release 3.0.0: one field resolution, loud context stacks, per-context blocks, registry-owned lazy counterparts by @trissim in #50
• Keep atomic and deferral block state per context (#30); rename legacy_entries (#34 item 3) by @trissim in #40
• Context stacks: with-only build_context_stack, scoped ancestors only, no layer skipped or substituted (#31, #34 items 1-2) by @trissim in #41
• Find a class's lazy counterpart through the base/lazy registry by @trissim in #42

Full Changelog: v2.1.1...v3.0.0