Bug#851357: Regression: No longer supports ServerName containing underscore

[Jonathan Vollebregt <jnvsor@gmail.com>]

Actually that makes another point: according to RFC952 hostnames are 
allowed only a single period:

http://www.ietf.org/rfc/rfc952.txt

>      <hname> ::= <name>*["."<name>]
>      <name>  ::= <let>[*[<let-or-digit-or-hyphen>]<let-or-digit>]

Unless this was updated in another RFC that means apache shouldn't even 
support subdomains in virtual hosts, and say goodbye to the .co.uk tld!

Furthermore the RFC2616 (HTTP/1.1) docs give an invalid hostname as 
their example for the Host request header:

https://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html#sec14.23

>       GET /pub/WWW/ HTTP/1.1
>       Host: www.w3.org

I think we can write this off as confusion due to the apache
documentation and say this is an actual bug and ServerName is supposed
to take domainnames