• Silence a warning about the deprecated spin_loop_hint.
• Relax ordering in the atomic set_max_level call.
• Add thumbv4t-none-eabi to targets that don't support atomics
• Allow levels to be iterated over.
• Implement Log on some common wrapper types.
• Improvements to test coverage.
• Improvements to documentation.
• Add key-value support to the log! macros.
• Tighten kv_unstable internal dependencies so they don't bump past their current alpha.
• Add a simple visit API to kv_unstable.
• Support NonZero* integers as values in structured logging
• Support static strings as keys in structured logging