rework classloader

- make it available in config
- always use classloader, no manual require
- compatible for future composer alternative

min_extras/tools/testRewriteUri.php

@@ -1,4 +1,7 @@
 <?php
+
+require dirname(__FILE__) . '/../../min/lib/Minify/Loader.php';
+
 header('Content-Type: text/html;charset=utf-8');
 
 function h($str) { return htmlspecialchars($str, ENT_QUOTES); }
@@ -55,4 +58,4 @@ if (isset($_POST['css'])) {
 <p><label>input CSS: <textarea name="css" cols="80" rows="5"><?php echo h(getPost('css', $defaultCss)); ?></textarea></label></p>
 <p><input type="submit" value="rewrite()" /></p>
 </form>
-<?php echo $out; ?>
+<?php echo $out; ?>