These are the response codes we'll use in SQCAS. The lower section (HTTPD_*)
are copied from Apache.
#define ERROR                              000

#define HTTP_CONTINUE                      100
#define HTTP_SWITCHING_PROTOCOLS           101
#define HTTP_PROCESSING                    102
#define HTTP_OK                            200
#define HTTP_CREATED                       201
#define HTTP_ACCEPTED                      202
#define HTTP_NON_AUTHORITATIVE             203
#define HTTP_NO_CONTENT                    204
#define HTTP_RESET_CONTENT                 205
#define HTTP_PARTIAL_CONTENT               206
#define HTTP_MULTI_STATUS                  207
#define HTTP_MULTIPLE_CHOICES              300
#define HTTP_MOVED_PERMANENTLY             301
#define HTTP_MOVED_TEMPORARILY             302
#define HTTP_SEE_OTHER                     303
#define HTTP_NOT_MODIFIED                  304
#define HTTP_USE_PROXY                     305
#define HTTP_TEMPORARY_REDIRECT            307
#define HTTP_BAD_REQUEST                   400
#define HTTP_UNAUTHORIZED                  401
#define HTTP_PAYMENT_REQUIRED              402
#define HTTP_FORBIDDEN                     403
#define HTTP_NOT_FOUND                     404
#define HTTP_METHOD_NOT_ALLOWED            405
#define HTTP_NOT_ACCEPTABLE                406
#define HTTP_PROXY_AUTHENTICATION_REQUIRED 407
#define HTTP_REQUEST_TIME_OUT              408
#define HTTP_CONFLICT                      409
#define HTTP_GONE                          410
#define HTTP_LENGTH_REQUIRED               411
#define HTTP_PRECONDITION_FAILED           412
#define HTTP_REQUEST_ENTITY_TOO_LARGE      413
#define HTTP_REQUEST_URI_TOO_LARGE         414
#define HTTP_UNSUPPORTED_MEDIA_TYPE        415
#define HTTP_RANGE_NOT_SATISFIABLE         416
#define HTTP_EXPECTATION_FAILED            417
#define HTTP_UNPROCESSABLE_ENTITY          422
#define HTTP_LOCKED                        423
#define HTTP_FAILED_DEPENDENCY             424
#define HTTP_INTERNAL_SERVER_ERROR         500
#define HTTP_NOT_IMPLEMENTED               501
#define HTTP_BAD_GATEWAY                   502
#define HTTP_SERVICE_UNAVAILABLE           503
#define HTTP_GATEWAY_TIME_OUT              504
#define HTTP_VERSION_NOT_SUPPORTED         505
#define HTTP_VARIANT_ALSO_VARIES           506
#define HTTP_INSUFFICIENT_STORAGE          507
#define HTTP_NOT_EXTENDED                  510

#define DOCUMENT_FOLLOWS    HTTP_OK
#define PARTIAL_CONTENT     HTTP_PARTIAL_CONTENT
#define MULTIPLE_CHOICES    HTTP_MULTIPLE_CHOICES
#define MOVED               HTTP_MOVED_PERMANENTLY
#define REDIRECT            HTTP_MOVED_TEMPORARILY
#define USE_LOCAL_COPY      HTTP_NOT_MODIFIED
#define BAD_REQUEST         HTTP_BAD_REQUEST
#define AUTH_REQUIRED       HTTP_UNAUTHORIZED
#define FORBIDDEN           HTTP_FORBIDDEN
#define NOT_FOUND           HTTP_NOT_FOUND
#define METHOD_NOT_ALLOWED  HTTP_METHOD_NOT_ALLOWED
#define NOT_ACCEPTABLE      HTTP_NOT_ACCEPTABLE
#define LENGTH_REQUIRED     HTTP_LENGTH_REQUIRED
#define PRECONDITION_FAILED HTTP_PRECONDITION_FAILED
#define SERVER_ERROR        HTTP_INTERNAL_SERVER_ERROR
#define NOT_IMPLEMENTED     HTTP_NOT_IMPLEMENTED
#define BAD_GATEWAY         HTTP_BAD_GATEWAY
#define VARIANT_ALSO_VARIES HTTP_VARIANT_ALSO_VARIES
