• FileSystem: messages use normalized paths (#250)
• Strings::indexOf() fixed empty $haystack and negative $nth #271
• Strings: improved things around flags
• Callback::unwrap can return non-callable #270
• used @return never
• added Helpers::clamp()
• Validators::isPhpIdentifier(): Value is always string. (#268)
• Reflection::expandClassName() recognizes 'parent'
• added Reflection::isClassKeyword(), Type::isClassKeyword()