Removing the addWizardPage function makes the code easier to follow.

The old implementation did always name the CustomWizardPage as "Details",
which is just wrong. Getting rid of this makes the page use its title as
the progress text, which is what we want in general anyway.

Change-Id: Iaf44f467c45952ad881154f31f62521f4f562658
Reviewed-by: Orgad Shaneh <orgads@gmail.com>