Execute Action at monitoring server failure.(deal with Issu 251)

Add a mechanism to do the action, when detected of the monitoring server failure (e.g. doesn't reply).

When Arm thread initializ, register trriger and monitoring server info.
when a failure was detected, Update the trigger and Register the event, and to perform the action(if registration).
Change to String from integer(uint64) the type of the variable, which be passed to JSON.

please confirm and comment.