Backport mod_cgi "CGI bucket" changes:

  * modules/generators/mod_cgi.c (log_script_err): Return a read error.
  (cgi_bucket_create, cgi_bucket_dup, cgi_read_stdout, cgi_bucket_read):
  New functions.
  (cgi_handler): Use new CGI bucket rather than a pipe bucket if
  APR_FILES_AS_SOCKETS; use zero read timeout from stdout/stderr during
  script execution.

  * modules/generators/mod_cgi.c (cgi_handler): Combine common code
  between nph and non-nph handling; use a CGI bucket for both cases if
  APR_FILES_AS_SOCKETS.

  * modules/generators/mod_cgi.c (cgi_handler): Soak up stderr from nph-
  scripts correctly.

PR: 18348, 22030
Submitted by: Joe Orton, Jeff Trawick
Reviewed by: Joe Orton, Jeff Trawick, Jean-Jacques Clar


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/APACHE_2_0_BRANCH@103968 13f79535-47bb-0310-9956-ffa450edef68