for licensing information please have look at core/img/filetypes/readme-2.txt

Without this clients won't see the update because they compare ctags
before fetching the actual calendar to reduce traffic.

Signed-off-by: Florian Pritz <bluewind@xinu.at>

Added stub function for loading categories.

This should make it possible to use owncloud with a read-only config.php

This way the config.php file is not changed every time you go to the
personal page. Step to make it possible to have a read-only config.php
most of the time