also cleanup confidential info from VTODO and VJOURNAL

Signed-off-by: Stefan Brüns <stefan.bruens@rwth-aachen.de>
fix handling of CLASS for VEVENT/VJOURNAL/VTODO

- use getAsString as CLASS is optional
- VJOURNAL/VTODO must be handled identical to VEVENT

Signed-off-by: Stefan Brüns <stefan.bruens@rwth-aachen.de>
use getAsString('CLASS') as CLASS is optional

Signed-off-by: Stefan Brüns <stefan.bruens@rwth-aachen.de>
Merge branch 'master' of https://github.com/StefanBruens/apps

Conflicts:
	calendar/lib/object.php