-adapt calls of make-error-response

-answer 501, not 405, for unimplemented/unrecognized methods

scheme/httpd/cgi-server.scm

@@ -124,17 +124,21 @@
 	(case (file-not-executable? filename)
 	  ((search-denied permission)
 	   (make-error-response (status-code forbidden) req
-				"Permission denied."))
+				"No permission to search directory."))
 	  ((no-directory nonexistent)
-	   (make-error-response (status-code not-found) req
-				"File or directory doesn't exist."))
+	   (make-error-response (status-code not-found) req))
 	  (else
 	   (if nph?
 	       (cgi-make-nph-response (run/port* doit))
 	       (cgi-make-response (run/port* doit) path req)))))
        
-       (else 
-	(make-error-response (status-code method-not-allowed) req request-method))))))
+       ((string=? request-method "HEAD")
+	    (make-error-response (status-code method-not-allowed) req (list "GET" "POST")))
+       
+       (else
+	(make-error-response (status-code not-implemented) req))))))
+
+	
 
 
 (define (split-and-decode-search-spec s)