mod_proxy: Add proxy-sendextracrlf option to send an extra CRLF at the

end of the request body to work with really old HTTP servers.

* modules/proxy/mod_proxy_http.c
  (stream_reqbody_cl, spool_reqbody_cl): If proxy-sendextracrlf option is
  present, append a CRLF to the body stream that isn't counted against CL.


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@157478 13f79535-47bb-0310-9956-ffa450edef68