add new option for X.509 name verification

add new option for X.509 name verification

Add the option --verify-x509-name to provide the functionality
of the now deprecated --tls-remote.

The new option accepts RFC 2253 subject DNs only and compares
RDN or RDN prefix only if configured explicitly.

Signed-off-by: Heiko Hund <heiko.hund@sophos.com>
Acked-by: Arne Schwabe <arne@rfc2549.org>
Message-Id: 1362670601-18660-1-git-send-email-heiko.hund@sophos.com
URL: http://article.gmane.org/gmane.network.openvpn.devel/7376
Signed-off-by: Gert Doering <gert@greenie.muc.de>
(cherry picked from commit 9f0fc745664fd0fc6a1c6785e101bf912088db16)