Triggered by the recent "Via:" header changes, the proxy module would

dump core for replies with invalid headers (e.g., duplicate
"HTTP/1.0 200 OK" lines). These errors are now logged and the
core dump is avoided. Also, broken replies are not cached.
Additionally, connection problems to an upstream server are now logged
in the error_log, besides being returned to client as before.


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/1.3.x@81965 13f79535-47bb-0310-9956-ffa450edef68