remove vichan's current antibot system

inc/config.php

@@ -275,83 +275,6 @@
 	// To prevent bump attacks; returns the thread to last position after the last post is deleted.
 	$config['anti_bump_flood'] = false;
 
-	/*
-	 * Introduction to vichan's spam filter:
-	 *
-	 * In simple terms, whenever a posting form on a page is generated (which happens whenever a
-	 * post is made), vichan will add a random amount of hidden, obscure fields to it to
-	 * confuse bots and upset hackers. These fields and their respective obscure values are
-	 * validated upon posting with a 160-bit "hash". That hash can only be used as many times
-	 * as you specify; otherwise, flooding bots could just keep reusing the same hash.
-	 * Once a new set of inputs (and the hash) are generated, old hashes for the same thread
-	 * and board are set to expire. Because you have to reload the page to get the new set
-	 * of inputs and hash, if they expire too quickly and more than one person is viewing the
-	 * page at a given time, vichan would return false positives (depending on how long the
-	 * user sits on the page before posting). If your imageboard is quite fast/popular, set
-	 * $config['spam']['hidden_inputs_max_pass'] and $config['spam']['hidden_inputs_expire'] to
-	 * something higher to avoid false positives.
-	 *
-	 * See also: https://github.com/vichan-devel/vichan/wiki/your_request_looks_automated
-	 *
-	 */
-
-	// Number of hidden fields to generate.
-	$config['spam']['hidden_inputs_min'] = 4;
-	$config['spam']['hidden_inputs_max'] = 12;
-
-	// How many times can a "hash" be used to post?
-	$config['spam']['hidden_inputs_max_pass'] = 12;
-
-	// How soon after regeneration do hashes expire (in seconds)?
-	$config['spam']['hidden_inputs_expire'] = 60 * 60 * 3; // three hours
-
-	// Whether to use Unicode characters in hidden input names and values.
-	$config['spam']['unicode'] = true;
-
-	// These are fields used to confuse the bots. Make sure they aren't actually used by vichan, or it won't work.
-	$config['spam']['hidden_input_names'] = array(
-		'user',
-		'username',
-		'login',
-		'search',
-		'q',
-		'url',
-		'firstname',
-		'lastname',
-		'text',
-		'message'
-	);
-
-	// Always update this when adding new valid fields to the post form, or EVERYTHING WILL BE DETECTED AS SPAM!
-	$config['spam']['valid_inputs'] = array(
-		'hash',
-		'board',
-		'thread',
-		'mod',
-		'name',
-		'email',
-		'subject',
-		'post',
-		'body',
-		'password',
-		'sticky',
-		'lock',
-		'raw',
-		'embed',
-		'g-recaptcha-response',
-		'h-captcha-response',
-		'captcha_cookie',
-		'captcha_text',
-		'spoiler',
-		'page',
-		'file_url',
-		'json_response',
-		'user_flag',
-		'no_country',
-		'tag',
-		'simple_spam'
-	);
-
 	// Enable simple anti-spam measure. Requires the end-user to answer a question before making a post.
 	// Works very well against uncustomized spam. Answers are case-insensitive.
 	// $config['simple_spam'] = array (