Additional errata for PE45

["Scott Cantor" <cantor.2@osu.edu>]

I located all the related messages and I believe the consensus was that my
wording for PE45 is acceptable, with the following additions:

Replace the paragraph at 1815-1819 with:

"Either a set of class references or a set of declaration references can be
used. If ordering is relevant to the evaluation of the request, then the set
of supplied elements MUST be evaluated as an ordered set, where the first
element is the most preferred authentication context class or declaration.
For example, ordering is significant when using this element in an
<AuthnRequest> message but not in an <AuthnQuery> message.

If none of the specified classes or declarations can be satisfied in
accordance with the rules below, then the responder MUST return a <Response>
message with a second-level <StatusCode> of
urn:oasis:names:tc:SAML:2.0:status:NoAuthnContext."

Jahan, you can probably merge this addition with the original one to replace
everything from 1815-1819 with this paragraph and the original addition I
submitted.

Finally, change current lines 1825-1827 to:

"If Comparison is set to "better", then the resulting authentication context
in the authentication statement MUST be stronger (as deemed by the
responder) than one of the authentication contexts specified."

This is a single word removed ("any one" becomes "one").

-- Scott