Omit redundant hostnames and hostnames with IDN domain names

[rdolezel]

I used Let's Encrypt win simple for the first time today. I use SNI on the server to enable multiple HTTPS websites listening on the same IP address without the need of SAN certificate. I also use multiple host-headers (including IDN domain) but only one HTTPS binding for my website.

I would like to ask you to implement two improvements:

1. do not offer the same hostname twice (once from HTTP binding, once from HTTPS binding probably)
2. remove any hostname containing national characters (ie. using IDN domain names) from the scanning results - from what I found Let's Encrypt CA does not plan to support IDN domains in a near future

Regards

Radek

[Bryan-Legend]

The client only scans for http bindings, because they're needed for the authorization process.

Looks like the IDN names should be filtered though.

[rkerber]

PR #71 hides IDN domains now.