New port: security/testssl.sh

testssl.sh is a command line tool which checks a server's service on
any port for the support of TLS/SSL ciphers, protocols as well as some
cryptographic flaws. Key features:

• Clear output: you can tell easily whether anything is good or bad
• Flexibility: You can test any SSL/TLS enabled and STARTTLS service, not only webservers at port 443
• Toolbox: Several command line options help you to run YOUR test and configure YOUR output
• Reliability: features are tested thoroughly
• Verbosity: If a particular check cannot be performed because of a missing capability on your client side, you'll get a warning
• Privacy: It's only you who sees the result, not a third party

WWW: https://github.com/drwetter/testssl.sh

Approved by: mat (mentor)
Differential Revision: https://reviews.freebsd.org/D11406