Update Smarty to 3.1.21

- add missing block.tphp, block.textformat.php, function.popup.php,
  function.popup_init.php
- update function in function.html_checkboxes.php,
  function.html_options.php

www/Smarty-3.1.21/plugins/modifiercompiler.strip.php

@@ -0,0 +1,33 @@
+<?php
+/**
+ * Smarty plugin
+ *
+ * @package    Smarty
+ * @subpackage PluginsModifierCompiler
+ */
+
+/**
+ * Smarty strip modifier plugin
+ * Type:     modifier<br>
+ * Name:     strip<br>
+ * Purpose:  Replace all repeated spaces, newlines, tabs
+ *              with a single space or supplied replacement string.<br>
+ * Example:  {$var|strip} {$var|strip:"&nbsp;"}<br>
+ * Date:     September 25th, 2002
+ *
+ * @link   http://www.smarty.net/manual/en/language.modifier.strip.php strip (Smarty online manual)
+ * @author Uwe Tews
+ *
+ * @param array $params parameters
+ *
+ * @return string with compiled code
+ */
+
+function smarty_modifiercompiler_strip($params)
+{
+    if (!isset($params[1])) {
+        $params[1] = "' '";
+    }
+
+    return "preg_replace('!\s+!" . Smarty::$_UTF8_MODIFIER . "', {$params[1]},{$params[0]})";
+}