#8 Calendar: Improvements for the messagebox

[Gerhard W. Gruber]

The messagebox should show the date/time when the event
has been scheduled.
Additionally it should have a "Remind me again in ..."
option. If the user uses this option the event should
be rescheduled. If the item is repeatable it should
just be rescheduled as if it were at this later
date/time. Only when the user presses OK it should be
recalculated for the next time it is scheduled
regularly. This would only affect normal items as bills
and countdowns dont have a messagebox.