[security-services] ISSUE: Format attribute for Issuer also

[RL 'Bob' Morgan <rlmorgan@washington.edu>]

I think the reasoning that justifies the "Format" attribute for Subject
NameIdentifier applies equally well to Issuer, since Issuer names also
will come in the same several standard formats as well as non-standard
ones, and it would be useful for RPs to be able to distinguish these.  I
note that this is consistent with RFC 2459, which specifies the use of
GeneralName syntax for IssuerAltName too.

So I suggest (as an ISSUE) that the schema for Issuer be modified to
permit the inclusion of the "Format" attribute for it too (sorry my schema
skills are limited, so I can't suggest the mod).

 - RL "Bob"