certsplainer: various fixes and graphical improvements
certsplainer: various fixes and graphical improvements

jasonthomas/tls-observatory,mozilla/tls-observatory,mozilla/tls-observatory,mozilla/tls-observatory,jasonthomas/tls-observatory,mozilla/tls-observatory,jasonthomas/tls-observatory,jasonthomas/tls-observatory,mozilla/tls-observatory,mozmark/tls-observatory,mozmark/tls-observatory,mozmark/tls-observatory,mozilla/TLS-Observer,jasonthomas/tls-observatory