Fixed example, please commit

This said, I thank a lot the person who started the

    > example since I used it as a starting point.

You should also thank that person because he (Jeremy O'Donoghue)
wrote the wx backend <wink>.

But the example was written a long time ago and since then many wx
users have contributed new/better/more/different wx examples
(embedding_in_wx[1-4].py) to atone for the original sins. I'm happy
to use your new/more/better/different example, but I'll first defer to
the wisdom of the resident wxperts, who may have some comments.