[xacml] Change to x500Name-equal function

[Anne Anderson <Anne.Anderson@Sun.com>]

I learned a lot from working on x500Name-match, and would like to
update x500Name-equal to be consistent as follows:

This function takes two arguments of "xacml:x500Name" and returns
"xs:boolean".  It returns true if and only if each Relative
Distinguished Name (RDN) in the two arguments matches.  Two RDNs
match if an only if the result of the following operations is true:

  First, normalize the two RDNs according to IETF RFC 2253
  "Lightweight Directory Access Protocol (v3): UTF-8
  String Representation of Distinguished Names Names".

  Second, if any RDN contains multiple attributeTypeAndValue
  pairs, re-order the attributeTypeAndValue pairs in that RDN in
  ascending order when compared as octet strings (described in
  ITU-T Rec. X.690 (1997 E) Section 11.6, "Set-of components").

  Finally, compare the RDNs using the rules in IETF RFC 3280
  "Internet X.509 Public Key Infrastructure Certificate and
  Certificate Revocation List (CRL) Profile", Section 4.2.1.4
  "Issuer".

Anne
-- 
Anne H. Anderson             Email: Anne.Anderson@Sun.COM
Sun Microsystems Laboratories
1 Network Drive,UBUR02-311     Tel: 781/442-0928
Burlington, MA 01803-0902 USA  Fax: 781/442-1692