Require minimum OpenSSL 1.0.1

Require minimum OpenSSL 1.0.1

As RHEL 5 has reached EOL, we no longer need to support OpenSSL v0.9.8.
This also makes it possible to remove a few workaronds which was
needed earlier, as well as some left overs from v0.9.6.

This also makes ./configure really stop running unless a new enough
OpenSSL library is found.

Compile tested on RHEL7.3 and RHEL6.7 (mock chroot build), both shipping
openssl-1.0.1e.

Signed-off-by: David Sommerseth <davids@openvpn.net>
Acked-by: Steffan Karger <steffan.karger@fox-it.com>
Message-Id: <20170411173133.18060-1-davids@openvpn.net>
URL: https://www.mail-archive.com/openvpn-devel@lists.sourceforge.net/msg14441.html
Signed-off-by: David Sommerseth <davids@openvpn.net>