WindowPlacement reads and writes a window's position, size and maximized
state under the names the WinForms app already stores (MainWindowLocation
"x, y", MainWindowSize "width, height", MainWindowState), in screen pixels.
A minimized window restores normal. FitTo drops a position that is on no
current screen and a size too big for its screen, as the WinForms main
window does when it restores.
