Change behavior of the show option

If the *show* option is set to ``true``, only the modal box is shown when initialized.
I don't think this makes much sense, because no card is shown so that the wizard is unusable and looks broken.

For this reason, I changed the behavior of the *show* option. When set to ``true``, the wizard will now be shown completely when initialized which is what you would expect from a *show* option.