v4.1.0

• Added:
  • Add the migration of the option to other option in the other group. For example, Group("g1").Migrate("opt1", "g1.opt2") will migrate the option opt1 in the group g1 to the option opt2 in the group g2, that's, when updating "g1.opt1", "g2.opt2" will be updated to the same new value, too.
• Changed:
  • Enhance the address validator NewAddressValidator.
  • Reduce the range of the group lock to avoid the deadlock when updating the option value in observer.