Merge r661506 from trunk:

* According to RFC 2616 8.2.3 we are not allowed to forward an
  Expect: 100-continue to an HTTP/1.0 server. Instead we MUST return
  a HTTP_EXPECTATION_FAILED.

Submitted by: rpluem
Reviewed by: jim, rpluem, niq


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/2.2.x@678203 13f79535-47bb-0310-9956-ffa450edef68