Add normalized dn to Entry structure as field e_ndn. Entry
creation codes to provide this field. Update cache_entrydn_cmp to strcasecmp() the e_ndn instead of e_dn. Note: strcasecmp() is still used as e_ndn isn't in uppercase. Maybe it should be. Did not update other codes to use e_ndn. Hence, there are lots of dn_normalize() calls that could be eliminated. (The case determination of e_ndn should be made first).