You will see a resizing tab in the lower right corner. This is confusing because resizing is kind
of incongruent with full screen. At first I thought dragging it might revert to full screen off, but
it actually resizes the image and stays in full screen.
* Lock the window size to cover the entire screen in full screen mode and remove the tab
* Change the name of the current option to something like "Borderless window" (if that is a
feature for some people)