hiding status messages after they're done

[pkra]

JAWS often reads "generating speech output" at "top" of page, i.e., when in browse mode, go to top of document (key up etc). Before the first h1 ("An example from Struik's...") it will read "generating speech output".

Maybe other status messages show up as well, I didn't test. It might be worth cleaning them up to avoid confusion.