Add clousures beside to delegates

[xandrefreire]

Based on issues #123

Now we can use closures instead of delegate.

Example:

mqtt.didReceiveMessage = { mqtt, message, id in
    print("Message received in topic \(message.topic) with payload \(message.string!)")           
}

Thanks.

[riccardoch]

I've downloaded version 1.1.1, but I can't add closures.
Hasn't this feature been released yet?

[HJianBo]

@riccardoch Yes, It will be contained in the next release version

If you want to use this feature, clone the latest on the master branch