add method: returnBeaconError

- (void) returnBeaconError: (NSUInteger) errorCode withMessage:
(NSString*) message
{
    NSMutableDictionary* posError = [NSMutableDictionary
dictionaryWithCapacity:2];
    [posError setObject: [NSNumber numberWithInt: errorCode]
forKey:@"code"];
    [posError setObject: message ? message : @"" forKey: @"message"];

    CDVPluginResult* pluginResult = [CDVPluginResult
resultWithStatus:CDVCommandStatus_ERROR messageAsDictionary:posError];
    for (NSString *callbackId in self.locationData.beaconCallbacks) {
        if (callbackId) {
            [self.commandDelegate sendPluginResult:pluginResult
callbackId:callbackId];
        }
    }
    self.locationData.beaconCallbacks = [NSMutableArray array];
}