Visible windows includes windows currently covered by other windows

[philocalyst]

Is this intended behavior? A window is not visible if it is currently covered by another -- it makes it very awkward to use focuseWindow[DIRECTION] as you would have to be aware of the entire window stack, or get in the habit of minimizing every window you use. Is there a convenience function workaround to get all windows that fit the current screen or something of that sort? Know I could workaround this but once again, just makes this a very uncomfortable function.

Open to feedback!!

:)