v1.3.0

• changeset get and fetch field (#41)
• Preload target type not changed if it is pointer (#44)
• handle empty struct and empty values when casting (#40)
• change should accept changed values (#46)
• Fix casting nil interface (#47)
• Pessimistic locking (#48)
• fix aggregate query (#49)
• fix mysql test in strict mode (#51)
• Allow disabling field escaping (#50)
• Form params (#45)
• fix nil params value field for alias type (#52)
• fix empty values when casting other changeset (#53)