refactor: use the new menu classes from master if available

This is still fully compatible with the current stable Frusterick
Manners, however these old method calls should be removed after the
release of Greebo.

main.php

@@ -140,7 +140,14 @@ $classWideContent = ($ACT === "show") ? "": "wide-content ";
 
                             <div class="menu-tool-select">
                                 <h5 class="sr-only" role="heading" aria-level="2"><?php echo tpl_getLang('head_menu_tool-select') ?></h5>
-                                <?php tpl_actiondropdown($lang['tools'], "test"); ?>
+                                <?php
+                                if (file_exists(DOKU_INC . 'inc/Menu/MobileMenu.php')) {
+                                    echo (new \dokuwiki\Menu\MobileMenu())->getDropdown();
+                                } else {
+                                    //Pre-Greebo Backwards compatibility
+                                    tpl_actiondropdown($lang['tools'], "test");
+                                }
+                                ?>
                             </div><!-- .menu-tool-select -->
                         </div><!-- .headings -->
                     </div><!-- .col -->