Allow apache acting as a proxy server to relay the real reason of a

failure to a client rather than the "internal server error" it does
currently. The general exposure mechanism can be triggered by any
module by setting the "verbose-error-to" note to "*"; this allows
more than just proxy errors to be exposed.

PR: 3455
Obtained from:
Submitted by: Cliff Skolnick <cliff@steam.com>
Reviewed by: Roy Fielding, Dirk-Willem van Gulik, Martin Kraemer


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/1.3.x@82814 13f79535-47bb-0310-9956-ffa450edef68