Gently push users towards --data-ciphers in --show-ciphers output

Gently push users towards --data-ciphers in --show-ciphers output

Also:
 * fix a typo in the openssl output ("may be use*d*")
 * mention GCM before CBC (we prefer AEAD modes)

Signed-off-by: Steffan Karger <steffan.karger@foxcrypto.com>
Acked-by: Arne Schwabe <arne@rfc2549.org>
Message-Id: <E1k011A-0002yw-8S@sfs-ml-2.v29.lw.sourceforge.com>
URL: https://www.mail-archive.com/openvpn-devel@lists.sourceforge.net/msg20608.html
Signed-off-by: Gert Doering <gert@greenie.muc.de>