Allow more fields to be optional in custom Page admins.
Allow more fields to be optional in custom Page admins.

See issue #536. When using a custom Page model and corresponding
admin class and still using the original PageAdminForm, you couldn't
disable the redirect_to and override_url (and less important: active)
fields because the form did not check first if they were in the
fieldset or not.

matthiask/feincms2-content,nickburlett/feincms,joshuajonah/feincms,matthiask/django-content-editor,michaelkuty/feincms,matthiask/django-content-editor,feincms/feincms,mjl/feincms,feincms/feincms,michaelkuty/feincms,joshuajonah/feincms,michaelkuty/feincms,nickburlett/feincms,matthiask/django-content-editor,joshuajonah/feincms,matthiask/feincms2-content,nickburlett/feincms,feincms/feincms,matthiask/django-content-editor,matthiask/feincms2-content,nickburlett/feincms,mjl/feincms,mjl/feincms,michaelkuty/feincms,joshuajonah/feincms