Conflict definition in SLAPI_ATTR_FLAG macros
    
    Bug description:
    It turned out these 2 macros had conflict values.
      SLAPI_ATTR_FLAG_NORMALIZED_CIS 0x0400 /* the attr value is normalized ..
      SLAPI_ATTR_FLAG_NOEXPOSE       0x0400 /* the attr value is not exposed */
    SLAPI_ATTR_FLAG_NORMALIZED_CIS was introduced with the commit
    c0151f78509c35250095da6e2785842337963008.
    
    Fix description: Define SLAPI_ATTR_FLAG_NOEXPOSE with 0x0800
    which is not used by any other SLAPI_ATTR_FLAG macros.