The main difference is that ping now reports icmp_seq instead of
icmp_req, so we match for icmp_.eq, which works with both releases.
tcpdump now also reports port 4500 as ipsec-nat-t.
With -W we reduce timeouts when we don't expect a response. With -i the
interval between pings is reduced (mostly in case of auto=route where
the first ping yields no reply).
Some fetcher plugins (such as curl) might build upon OpenSSL to implement
HTTPS fetching. As we set (and can't unset) threading callbacks in our
openssl plugin, we must ensure that OpenSSL functions don't get called after
openssl plugin unloading.
We achieve that by loading curl and all other fetcher plugins after the base
crypto plugins, including openssl.
