Ticket 79 - Add assertion that event is not registerd during rearm
    
    Bug Description:  During a rearm, we assert the event is not in the
    event framework.
    
    Fix Description:  When the event triggers, it's removed from the fw
    and it's re-added on re-arm via mod. This adds an abort() during
    DEBUG to prove the correctness of this.
    
    https://pagure.io/nunc-stans/issue/79
    
    Author: wibrown
    
    Review by: mreynolds (Thanks!)