改变了菜单树，链接和标签显示函数

(Issue)

function menu_tree_output() now returns a structured array of data that can be rendered to html using drupal_render().

Function theme_menu_item_link() and theme_menu_item() have been removed and are effectively replaced by in terms of rendering a menu tree by theme_menu_link(). This is the default function used to render each link in the tree returned by menu_tree_output().

Function theme_menu_local_task() takes different parameters and has a companion theme_menu_local_action() that did not exist in Drupal 6. Both of these function take as the first parameter a menu link array with 'title', 'href', and 'localized_options' keys. In Drupal 6, the first parameter was a string. The change to array was made in order to allow removal of theme_menu_item_link(). The second parameter theme_menu_local_task() of is still a boolean, $active.