Change core connection handling so that a connection-oriented

Change core connection handling so that a connection-oriented
error disabling nagle* is logged with the client IP address and
a debug log level.  We filter out not-implemented errors from
platforms which don't support TCP_NODELAY.

*This is typically EINVAL, which means that the client already
dropped the connection.

Also, mention an earlier change to include the client IP address
when logging connection-oriented errors.

git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@105652 13f79535-47bb-0310-9956-ffa450edef68