The window is simply ignored in the painting and hit testing traversal
when in minimized state, same as we do for invisible windows.
The WM_SetActiveWindow message (sent by Taskbar) brings it back into the
non-minimized state. :^)
Previously it would just close the window on MouseDown. Now we do the normal
thing where we require a MouseUp inside the button rect before committing.
The window frame is an object that contains a window, its title bar and
window border. This way WSWindowManager doesn't have to know about all the
different types of window borders, titlebar rects, etc.
These events are identical, so it's silly to send both. Just broadcast
window state changes everywhere instead, it doesn't matter when it was
added as clients are learning about this asynchronously anyway.
I originally thought I would do this inside WindowServer, but let's try to
make it as a standalone app that communicates with WindowServer instead.
That will allow us to use LibGUI. :^)
