Solution for host-meta

[Eran Hammer-Lahav <eran@hueniverse.com>]

I don't know why I didn't think about this before. As indicated in my last email, this is what I propose we do:

* Drop the match attribute.
* host-meta will use <Subject> with the string 'host-meta://example.com:80'.
* host-meta will state that the string is not a valid URI and is only used for trust purposes.

Since XRD <Subject> has no current requirement for the URI scheme to be valid or registered, only that the syntax of the string comply with RFC 3986, this solves everyone's problem without actually having to create/register a new URI scheme.

EHL