 
mod_cgi: CGI scripts execution support

http_script: keeps all script-related ramblings together.
Compliant to CGI/1.1 spec
Adapted by rst from original NCSA code by Rob McCool

Apache adds some new env vars; REDIRECT_URL and REDIRECT_QUERY_STRING for
custom error responses, and DOCUMENT_ROOT because we found it useful.
It also adds SERVER_ADMIN - useful for scripts to know who to mail when 
they fail.
 
