Ticket 47541 - Replication of the schema may overwrite
     consumer 'attributetypes' even                 if
     consumer definition is a superset
    
    Bug Description:  Need to check consumer attributetypes to make sure it doesn't get
                      overwritten if it is a superset.
    
    Fix Description:  First, extended the attribute syntax struct to make it a double
                      linked list.  This allows us to easily look through all the attributeTypes.
                      Then check for supersets by looking at single vs multi-valued, and
                      syntax oid's.  Matching rules are not being evalauated at this time.
    
    https://fedorahosted.org/389/ticket/47541
    
    Reveiwed by: rmeggins(Thanks!)