As a user, I want to be able to view error notifications even if I don't attend while they occur. Therefore, notification durations should be configurable and it should be possible to disable automatic closing of notifications.
Notification duration of -1 means notifications stays open until the user manually closes it
Durations configurable independently for each severity (Info, Warning, Error)
Durations are denoted in seconds
If possible, use config file org.opencastproject.organization.cfg