The portal package can replace the standard acs-subsite user interface.
<p>If you choose to
replace the parent acs-subsite's index page with the portal index page, the only pages to visible
to the visiting user will be those protal pages you created earlier.
<p>If you choose to replace the parent acs-subsite's master template, both portal pages and
the pages normally displayed by the acs-subsite "tabbed" master template will be shown.
<formtemplate id="configure-subsite-integration"></formtemplate>