Enable regular expressions when searching data in all tables

Allows use of the database-specific regex operator and pattern syntax when searching multiple tables.

editor/include/adminer.inc.php

@@ -1,6 +1,7 @@
 <?php
 class Adminer {
 	var $operators = array("<=", ">=");
+	var $operator_regexp = null;
 	var $_values = array();
 
 	function name() {