Instant Borderless

Fixed F11 not leaving exclusive fullscreen. After switching to Fullscreen in Video Settings, F11 only flipped the borderless setting and the game stayed in exclusive fullscreen. F11 now leaves it as in vanilla, and borderless mode is re-applied if it is on.

Borderless mode now follows monitor changes. Plugging a monitor in or out, or changing a monitor's resolution, refits the window to its monitor instead of leaving it at the old size and position.

The window size and position from before borderless mode are now remembered across restarts. Previously, turning the mode off after starting the game in it left the default 854x480 window. A saved position on a monitor that is no longer connected is not restored; the window is centered on its current monitor instead.