I've added very simple MQTT-based feature that allows to monitor device connectivity.

• MQTT connector component will now use %deviceprefix%/connected topic to inform about connection state.
• Just after establishing MQTT connection, ksIotFrameworkLib will post "1" value to the topic.
• Last will message feature of MQTT protocol will post "0" value to the %deviceprefix%/connected topic.

Thanks to my Blynk-MQTT-Bridge I was able to setup uptimerobot easily: