docs: Further improve --reneg-bytes and SWEET32 information

docs: Further improve --reneg-bytes and SWEET32 information

There are still some support tickets related to SWEET32 and
our defult enforced --reneg-bytes 64 when using weaker ciphers
(less than 128-bits cipher blocks).  Try to clarify this even
more.

Also fix a few mistakes, saying less than 128-bits and not 128-bits
and less.

Signed-off-by: David Sommerseth <davids@openvpn.net>
Acked-by: Steffan Karger <steffan@karger.me>
Message-Id: <1482353691-27088-2-git-send-email-davids@openvpn.net>
URL: https://www.mail-archive.com/openvpn-devel@lists.sourceforge.net/msg13662.html