Allow journals to have Attendees (strange terminology). This extends our icalendar implementation, so they can be sent as groupware mails and can be made visible to others on groupware servers (supported in GroupWise at the moment). Journals now use an edit dialog to add a new journal, and should be edited with the new edit button to change attendees. They can also be edited inline as before. Also fixes an infinite loop bug in Korganizer when editing journals

svn path=/branches/KDE/3.5/kdepim/; revision=439539