Bug 697961 - memberOf needs to be triggered by internal operations
    
    The memberOf plug-in is not currently triggered by internal modify,
    add, delete, or rename operations.  This patch makes it work with
    internal operations so it can play nicely with other plug-ins that
    make membership changes, such as the new Auto Membership plug-in.
    
    The precedence for the referential integrity plug-in needed to be
    lowered to ensure consistency of membership attributes when both
    memberOf and referential integrity plug-ins are in use.