Don't expire notifications when the timeout expires

[leolost2605]

We only close the window but don't send the notification_closed signal. That's because they are still visible in the notifications indicator and can still receive input/responses especially with elementary/wingpanel-indicator-notifications#263.

Fixes #104 Closes #212

[Marukesu]

i would like to restore the expiration feature in the future, so a simpler way to remove the expiration now is to remove src/DBus.vala:156.

[leolost2605]

But wouldn't that also prevent the signal from clicking the close button from being emitted?

[Marukesu]

take a more thought look at this, i believe the right way to go here is something along this lines:

   bubble[id].closed.connect ((res) => {
       if (res is EXPIRED && app_settings.get_boolean ("remember")) {
           return;
       }

       notification_closed (id, res);
   });

that will make sure that we keep expiring the notifications that shouldn't go to the tray.

[leolost2605]

@Marukesu nice, I updated it accordingly!

[leolost2605]

Causes #212

[danirabbit]

@leolost2605 can you resolve conflicts here?

[leolost2605]

@danirabbit done.

[danirabbit]

@Marukesu Do you still approve here? :)