Also use OC_User::isLoggedIn to check if new authentication is needed for grouplist.php and userlist.php
For validateuser.php, credentials are always needed.

Functions to get the token of a public link now stored by OC_Share, remove no longer needed ajax call to getlink.php

make the help section working and pretty. knowledge base entries are fetched via OCS from a different server. cool stuff

Info about which groups the users belong to are also in the user list. Both files need logging in through GET because unauthorized users are not allowed to see this data.