Notifications should offer to open the event window

[humdingerb]

No matter if it's a simple BAlert, a BNotification, or some custom solution, the notification should make it possible to open Calendar's Event window of the specific event. The user may want to see the details (description, attachments...) or reschedule.

It could open the main Calendar app with a hidded main window, only the Event window open. Maybe some added flag in message launching Calendar?