Added MQTT support

Hi Brian,

I ended up setting up a mqtt broker via CloudMqtt and WD is successfully able to update it.

YEsterday though the CloudMqtt server I connect to had a harware failure and was offline for a few hours - the WD mqtt connection program obviously disconnected. When the server came back up, I had to manually re-connect via the Connect button in the WD mqtt window.

Is it possible for an auto connection retry to occur, say once every 10 mins or so?

Thanks
ian