Deal with long hostnames by making use of the MAXHOSTNAMELEN symbol

when available, or 256 (the Internet default) when not.

Submitted by: Dean Gaudet
Reviewed by: Roy Fielding, Chuck Murcko


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/1.3.x@77718 13f79535-47bb-0310-9956-ffa450edef68