Public action logs commit (log.php)

Note: In a previous commit, I began making inc/mod/auth.php more modular with the check_login() function. Including it does NOT check mod login by default anymore like it does on vichan. You have to call check_login(). I've finally included it in inc/functions.php. If you have any custom pages that use inc/mod/auth.php, just including functions.php is enough now.

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Also: backports 351375185e5 (early 404)

install.sql

@@ -65,6 +65,7 @@ CREATE TABLE IF NOT EXISTS `boards` (
   `uri` varchar(58) CHARACTER SET utf8 NOT NULL,
   `title` tinytext NOT NULL,
   `subtitle` tinytext,
+  -- `indexed` boolean default true,
   PRIMARY KEY (`uri`)
 ) ENGINE=MyISAM DEFAULT CHARSET=utf8mb4;