Now *can* retrieve attributes for LDAP!

[Erdos, Marlena]

Huge thanks, Michael, Peter, Brent, and  Scott!    I got a boatload of
attributes from after the fixes. Yippee!

I had two errors in my filter invocation: I was missing curly braces and I
was using "principal" instead of "principalName". (I'm setting "principal"
in the http header that my actual external authN
system returns to my external authN servlet co-located with the IdP.  I'd
forgotten that the servlet turns the "principal" contents into
"PRINCIPAL_NAME_KEY" in  its "returnToAuthenticationEngine" call.)

Here is the working filter invocation.

<dc:FilterTemplate>
            <![CDATA[
                (harvardeduidnumber=${requestContext.principalName})
            ]]>
        </dc:FilterTemplate>


Thank you again!  It was great to get the connection to LDAP working
before the weekend.

My best,
Marlena