NoVNC: Remove the "Connect" window when app closes

Is there a way to remove the NoVNC “Connect” window that shows up when a user exits out of an app? This is one of the main items we get feedback on that confuses users. Maybe also just close the tab entirely?

@shawn.doughty I spent a chunk of today looking into how this could be done. Have a look at https://github.com/OSC/ood-dashboard/pull/456 for my and @efranz’s thoughts on how to improve the message. It would be a poor user experience if we caused the window to close automatically, because that leave users confused about where their window went if for example their batch job timed out while they were not paying attention. Instead I prefer to change the message:

I ended up patching base.css and vnc.html Works well, thanks!