acknowledge notification messages

[Jerad Whitaker]

When running a backup, if an error occurs, a notification window pops up on the user's desktop.  It will continue to popup about every 15 minutes.  The only way I have found to acknowledge to the NAS that I have seen this message is to delete the backup task that generated the error.  This doesn't seem like the right way to answer notification messages.  I would like to be able to check somewhere that I have seen the message and not to display it again.  The options to do that do appear in the message but don't actually change anything, the message keeps coming back.  I don't know if this should be a new feature of a bug fix, but I think it should be one of those.