Replacing old function get_user_info_from_id() with api_get_user_info()
Minor - Fixing wrong class name
Creating new folders due a new structure see #5871
Adding new URLs web/certificates/1, web/users/admin and web/news/1 instead of certificates/index.php?id=1 user.php?u=admin (probably never used) and news_list.php?id=1
Paths changes due the new structure see #5871 (pending confirmation)
Adding missing function (due recent merge of social group into social class) + using api_get_user_language() instead of a $_SESSION variable