--management-external-key for PolarSSL

--management-external-key for PolarSSL

Add --management-external-key support, compatible with the OpenSSL
implementation. Needs the flexibility of ssl_set_own_cert_alt(), which
is new in PolarSSL-1.2.

Signed-off-by: Joachim Schipper <joachim.schipper@fox-it.com>
Signed-off-by: Steffan Karger <steffan.karger@fox-it.com>
Acked-by: Arne Schwabe <arne@rfc2549.org>
Message-Id: <1379587649-25506-3-git-send-email-steffan.karger@fox-it.com>
URL: http://article.gmane.org/gmane.network.openvpn.devel/7886
Signed-off-by: Gert Doering <gert@greenie.muc.de>
(cherry picked from commit 38ace48c6820c611e689bc69b0cf5380bf7a8891)