Window state saved when second screen disconnected

[Ryan Schuetzler]

I sometimes use a second monitor, and sometimes I don't. If an app has window-state.json stored with a location on the second monitor, then the second monitor is disconnected, I cannot see the app when the app is launched again. It is launched off the screen, and the only way I can figure to bring it back is to delete window-state.json. Using Win+left doesn't move it, it just stays there.

[Marcel Wiehle]

See #44