Ticket 47963 - RFE - memberOf - add option to skip nested
     group lookups during delete operations
    
    Bug Description:  The recursive nested group lookups performed during a group delete
                      operation can take a very long time to complete if there are very
                      large static groups(groups with with over 10K members).
    
                      If there are no nested groups, then it would be nice to have an option
                      to skip the nested group check, which would significantly improve
                      delete performance.
    
    Fix Description:  Added a new memberOf plugin configuration attribute:
    
                          memberOfSkipNested: on|off
    
    https://fedorahosted.org/389/ticket/47963
    
    Reviewed by: rmeggins(Thanks!)