MEDIUM: http-rules: Rely on http reply for http deny/tarpit rules

"http-request deny", "http-request tarpit" and "http-response deny" rules now
use the same syntax than http return rules and internally rely on the http
replies. The behaviour is not the same when no argument is specified (or only
the status code). For http replies, a dummy response is produced, with no
payload. For old deny/tarpit rules, the proxy's error messages are used. Thus,
to be compatible with existing configuration, the "default-errorfiles" parameter
is implied. For instance :

  http-request deny deny_status 404

is now an alias of

  http-request deny status 404 default-errorfiles
diff --git a/include/types/action.h b/include/types/action.h
index 8d68f6d..b01380c 100644
--- a/include/types/action.h
+++ b/include/types/action.h
@@ -125,11 +125,7 @@
 			struct list fmt;       /* log-format compatible expression */
 			struct my_regex *re;   /* used by replace-header/value/uri/path */
 		} http;                        /* args used by some HTTP rules */
-		struct {
-			int status;            /* status code */
-			struct buffer *errmsg; /* HTTP error message, may be NULL */
-		} http_deny;                   /* args used by HTTP deny rules */
-		struct http_reply *http_reply; /* HTTP response to be used by return rules */
+		struct http_reply *http_reply; /* HTTP response to be used by return/deny/tarpit rules */
 		struct redirect_rule *redir;   /* redirect rule or "http-request redirect" */
 		struct {
 			char *ref;             /* MAP or ACL file name to update */