• Impl Default for Value; the default Value is Value::Null (#226, thanks @killercup)
• Fix a bug that could successfully deserialize enums from invalid JSON (#230, thanks @killercup)
• Allow to_value to serialize maps with integer keys, matching the behavior of to_string (#231, thanks @killercup)
• Impl PartialEq for Value to simplify comparisons with various primitive types (#235, thanks @imp)