1st cut of 'simple' tcp check... We reuse various proxy

function and so this *could* be more streamlined, but
use this to show how the other would work, since we need
brigades, SSL/TLS support, etc.

git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1724879 13f79535-47bb-0310-9956-ffa450edef68