Added

• add support for variadic options (#1250)
• allow options to be added with just a short flag (#1256)
  • Breaking the option property has same case as flag. e.g. flag -n accessed as opts().n (previously uppercase)
• Breaking throw an error if there might be a clash between option name and a Command property, with advice on how to resolve (#1275)

Fixed

• Options which contain -no- in the middle of the option flag should not be treated as negatable. (#1301)