handle AUX switches (CH7, CH8) settings

def cmd_auxopt(self, args):
        '''handle AUX switches (CH7, CH8) settings'''
        if self.mpstate.vehicle_type != 'copter':
            print("This command is only available for copter")
            return
        if len(args) == 0 or args[0] not in ('set', 'show', 'reset', 'list'):
            print("Usage: auxopt set|show|reset|list")
            return
        if args[0] == 'list':
            print("Options available:")
            for s in sorted(aux_options.keys()):
                print('  ' + s)
        elif args[0] == 'show':
            if len(args) > 2 and args[1] not in ['7', '8', 'all']:
                print("Usage: auxopt show [7|8|all]")
                return
            if len(args) < 2 or args[1] == 'all':
                self.aux_show('7')
                self.aux_show('8')
                return
            self.aux_show(args[1])
        elif args[0] == 'reset':
            if len(args) < 2 or args[1] not in ['7', '8', 'all']:
                print("Usage: auxopt reset 7|8|all")
                return
            if args[1] == 'all':
                self.param_set('CH7_OPT', '0')
                self.param_set('CH8_OPT', '0')
                return
            param = "CH%s_OPT" % args[1]
            self.param_set(param, '0')
        elif args[0] == 'set':
            if len(args) < 3 or args[1] not in ['7', '8']:
                print("Usage: auxopt set 7|8 OPTION")
                return
            option = self.aux_option_validate(args[2])
            if not option:
                print("Invalid option " + args[2])
                return
            param = "CH%s_OPT" % args[1]
            self.param_set(param, aux_options[option])
        else:
            print("Usage: auxopt set|show|list")