Merge of r4372, r4373, r4374:

Merge of r4372, r4373, r4374:

SCGI fixes:

*) Fixed incorrect use of r->http_version in scgi module.

   The r->http_version is a version of client's request, and modules
   must not set it unless they are really willing to downgrade protocol
   version used for a response (i.e. to HTTP/0.9 if no response headers
   are available).  In neither case r->http_version may be upgraded.

   The former code downgraded response from HTTP/1.1 to HTTP/1.0 for no
   reason, causing various problems (see ticket #66).  It was also
   possible that HTTP/0.9 requests were upgraded to HTTP/1.0.

*) Removed duplicate function declaration.

*) Removed error if there is no Status header.

   The SCGI specification doesn't specify format of the response, and
   assuming CGI specs should be used there is no reason to complain.
   RFC 3875 explicitly states that "A Status header field is optional,
   and status 200 'OK' is assumed if it is omitted".