Handle CLI switches related to hear_beat / keep-alive functionality.

Set heart_beat's value (increment periodically). THis will trigger a publish event to all subscribers.

Add a heart beat variable which is published. Remove PubSub over Ethernet/UADP as simply not plans to use directly Ethernet directly.

Remove duplicating section just for the sake of name of the C compiler as by default gcc is a symbolic link which will point proper one.