https://github.com/Neilpang/acme.sh/issues/1246
fix https://github.com/Neilpang/acme.sh/issues/1188#issuecomment-357684744
https://github.com/Neilpang/acme.sh/issues/1130 https://github.com/Neilpang/acme.sh/issues/990
change back to use openssl for tls mode.
use socat instead of nc.
fix https://github.com/Neilpang/acme.sh/issues/939
don't trigger validation for dns manually mode