Making $data parameter required in Set::matches.

Refs #993.

This has been a leftover of a previous refactor (9084d69).
This patch changes signature as per documentation.

It can be expected that as the second parameter must be given, the first
must also always be given, so this doesn't break BC.

util/Set.php

@@ -584,7 +584,7 @@ public static function isNumeric($array = null) {
 	 * @param integer $length
 	 * @return boolean
 	 */
-	public static function matches($data = array(), $conditions, $i = null, $length = null) {
+	public static function matches($data, $conditions, $i = null, $length = null) {
 		if (!$conditions) {
 			return true;
 		}