ADS: Added KeepAlive Settings to the ApplePush Channel to aid with Azure...

... hosting.

I didn't add it to IPushChannelSettings as GCM doesn't maintain a socket connection and I don't have prior knowledge of the other channels to implement.

Hope you find it useful. The defaults are 20 mins and 30 secs as per the hardcoded values.

Cheers
Don't you want this to be .TotalMilliseconds for both cases?