Handle views from removed outputs (virtual outputs?) #45

I'm not sure if moving clients to active plugged monitor is good idea. It might work on stacking wms (even there annyoining). I should move the control logic from wlc to wm for this.

In i3 where there are no separate workspaces per output (by default at least), they don't need to think about this since the workspace from the another monitor will just appear on primary one after the other one is removed.

What I imagine is good and flexible system, is create a virtual output after output is unplugged and it has at least one client on it. The virtual output switches like workspace on single output, but acts like actual output, meaning your workspace list etc change. This allows you to modify the layout on virtual output and plug the monitor back in later and it will just work. You may also destroy the virtual output, as to say "I don't care about these clients anymore, and I don't plan restoring the layout when I plug output back in".

The only problem with this approach is the indication of active output which will be very confusing without any panel, or other indication what is active.

This is something that sounds very intuitive to me however, if different kind of behavior gets votes, Its always possible to make alternatives and split them to plugins.