core: Stop ap_finalize_request_protocol() and ap_get_client_block() from silently

swallowing errors from the filter stack, create error buckets and return them
appropriately.


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1482918 13f79535-47bb-0310-9956-ffa450edef68