Ticket 48208 - CleanAllRUV should completely purge changelog
    
    Bug Description:  After cleanAllRUV finishes, the changelog still
                      contains entries from the cleaned rid.  Under certain
                      conditions this can allow the RUV to get polluted
                      again, and the ruv element will be missing the replica
                      url.
    
    Fix Description:  At the end of the cleaning task, fire of a thread to
                      to completely purge the changelog of all entries
                      containing the cleaned rid.
    
                      Also, improved the cleanAllRUV task when dealing
                      with a server shutdown - previously if the timing is
                      right the task can "delay/hang" the shutdown process.
    
    https://fedorahosted.org/389/ticket/48208
    
    Reviewed by: nhosoi(Thanks!)