Re: [xri] subject sets

I have finally read through this entire thread (which started when I was on
vacation). If I understand it all (which is not a safe assumption ;-), my
feedback is:

1) I agree simplicity is maximized if there is just an <XRD:Subject> element
with a single attribute, and that single attribute initially takes a single
value.

2) I'd suggest the attribute name "match", e.g., <XRD:Subject
match="beginswith">

3) No "match" attribute = exact URI match required.

4) Comparisions of Subjects across Links should be: a) exact match on the
URI value after normalization, and b) exact match on the attribute value,
all lowercase.