Fix the url_for function missing when render menu and feed urls.
Fix the url_for function missing when render menu and feed urls.

ganyuanda/hexo-theme-next,happsky/happsky.github.com,mchsinx/hexo-theme-next,FluencyLiu/hexo-theme-next,zhipengyan/hexo,iissnan/hexo-theme-next,Austaras/hexo-theme-next,zhipengyan/hexo,flashlab/hexo-theme-next,chaoskyme/hexo-theme-next,chaoskyme/hexo-theme-next,geekrainy/hexo-theme-next,cragod/hexo-theme-next,happsky/happsky.github.com