Add debugging info to the HttpProtocolOption directive doc

In bugzilla and users@ we keep receiving questions about
how to test the new restrictions imposed by HttpProtocolOptions.
Added some info about how to use openssl s_client properly
and the mod_dumpio's directives to debug (thanks to
Daniel Ferradal for this suggestion).



git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1782140 13f79535-47bb-0310-9956-ffa450edef68