Add http_anchors, _revoke, and _hostname settings

Add http_anchors, http_revoke, http_hostname and
http_require_crl_checking settings, mimicking both the locations and
effects of their similarly-named PKINIT counterparts, but affecting
HTTPS connections to KDC proxy servers.

The hostname checking currently assumes UTF-8 everywhere.
Add a simple KDC proxy test server

This proxy server uses python-paste to run the kdcproxy from
https://pypi.python.org/pypi/kdcproxy.  It should be used along
with the proxy.pem certificate in ../tests/dejagnu/proxy-certs.
Add tests for MS-KKDCP client support

Exercise the MS-KKDCP client support using the test proxy server, for
AS, TGS, and kpasswd requests while also checking the certificate
verification and revocation and name checks.