Add a "Do Not Disturb" setting to prevent interruptions/notifications

[Greg Williams]

Some poor usability decisions made by the Ubuntu-Unity team (e.g., see https://bugs.launchpad.net/ubuntu/+source/unity/+bug/1346355) have resulted in too many distractions when trying to work on projects.

As discussed in Bug #1346355, not having a perpetual indicator that indicates a restart is needed, users do not remember the computer needs restarting. Hence, they are always dealing with popups that interrupt their workflow.

Gnome-Shell offers a "Do Not Disturb" setting that prevents notifications from occurring. Ubuntu/Unity needs the same.

When "Do Not Disturb" is enabled, no notifications should post and no Launcher icons should "popout" from the left margin of the screen (as they do when the Launcher is set to "Auto-Hide"). Do Not Disturb should suppress all manner of popups, popouts, etc.

[Paul Slater (pslater)]

And it should have a periodic scheduler to enable mad disable it.

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.