Dev
fix https://github.com/Neilpang/acme.sh/issues/508
secure debug message
fix syslog doc
fix syslog level
fix syslog
minor use interactive _sleep
fix for freebsd
compatible to openssl 0.9 for hmac function
Nonce
fix https://github.com/Neilpang/acme.sh/issues/627
fix https://github.com/Neilpang/acme.sh/issues/614
support nginx mode
(this isn't working 100% yet, still looking for a solution)
Export curl header variables.