some fastcgi improvements:

some fastcgi improvements:
- DPRINTF instead of log_info for internal debugging.
- submit QUERY_STRING, if it exists
- use a proper function to create an HTTP header.
- use server_file_error() to detect EOF and fastcgi stream errors.
- disable keep-alive/persist for now until we have a reliable way to
get the content length from the cgi response or support chunked
encoding.

"Cool, jep" florian@